Trace and analyze blockchain transactions to investigate illicit fund flows, identify wallet clusters, and map transaction graphs across multiple blockchains. Use when investigating stolen funds, following money trails on-chain, analyzing suspicious addresses, or tracing cross-chain transactions.
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Trace and analyze blockchain transactions to investigate illicit fund flows, identify wallet clusters, and map transaction graphs across multiple blockchains. Use when investigating stolen funds, following money trails on-chain, analyzing suspicious addresses, or tracing cross-chain transactions.
Blockchain transaction forensics involves tracing and analyzing cryptocurrency transactions to investigate illicit fund flows, identify wallet clusters, and map transaction graphs across multiple chains. Unlike traditional financial forensics, blockchain provides a public, immutable ledger where every transaction is permanently recorded. Every hop a stolen fund takes — from initial theft through mixers, bridges, DEX swaps, and exchange deposits — leaves indelible evidence.
This skill covers collecting transaction data via block explorer APIs and RPC nodes, building directed transaction flow graphs with NetworkX, applying clustering heuristics (peel chain detection, consolidation patterns, CoJoin clustering for UTXO chains, address reuse), identifying mixing services and cross-chain bridges by scanning event logs and known contract registries, and producing investigator-ready trace reports with Sankey flow visualization. The techniques here apply to EVM chains (Ethereum, BNB Chain, Polygon, Arbitrum, Optimism, Avalanche), Bitcoin-family UTXO chains, Solana, and TRON.
When to Use
Trigger phrases:
"onchain transaction forensics"
"Trace stolen funds on the blockchain"
"Follow the money on-chain"
"Analyze suspicious wallet transactions"
"Where did the stolen crypto go"
"Fund flow analysis"
"Blockchain investigation"
When investigating theft, rug pull, or hack incidents that require tracing stolen cryptocurrency
When building evidence chains for law enforcement or bounty submissions (Arkham, Lazarus Bounty)
When analyzing suspicious wallet activity for compliance or risk assessment
When reconstructing the flow of funds through mixers, bridges, or exchanges
When preparing transaction trace reports as a paid forensic service
When mapping the flow of illicit funds from a known attacker address
When performing due diligence on a large transaction or wallet before a business deal
When NOT to Use
You need real-time monitoring of transactions (use a blockchain monitoring service or webhook provider)
Step 1: Collect All Transactions for Target Addresses
Start with the primary address from the incident — the theft wallet, the hacker's known address from a Rug Pull, or the suspicious deposit address.
def collect_all_txs(address: str, api_key: str, chain_id: int = 1) -> dict:
"""Collect normal, internal, and ERC-20 tx history for one address."""
return {
"normal": get_txs_v2(address, api_key, chain_id),
"internal": get_internal_txs_v2(address, api_key, chain_id),
"erc20": get_erc20_transfers_v2(address, api_key, chain_id),
}
Normal TXs: Standard ETH/BNB/MATIC transfers where from and to are directly visible
Internal TXs: Transfers triggered by contract CALL opcodes — these are NOT visible in normal tx lists but move ETH. Critical for tracing through DEX swaps, DeFi interactions, and bridge deposits
ERC-20 transfers: Token movements (transfer events). The most common value transfer mechanism in DeFi hacks
ERC-721 / ERC-1155: NFT transfers. Relevant for NFT theft and phishing investigations
Pagination: Etherscan API returns up to 10,000 rows per call. For addresses with more transactions, pass the page parameter:
def collect_all_txs_paginated(address: str, api_key: str, chain: str = "ethereum",
max_pages: int = 10) -> list[dict]:
"""Paginate through large transaction histories."""
client = ExplorerClient(api_key, chain)
all_txs = []
for page in range(1, max_pages + 1):
params = {
"module": "account", "action": "txlist",
"address": address, "startblock": 0,
"endblock": 99999999, "sort": "asc",
"page": page, "offset": 10000
}
txs = client._call(params)
if not txs:
break
all_txs.extend(txs)
if len(txs) < 10000:
break
return all_txs
Step 2: Parse and Normalize Transaction Data
Parse the raw API responses into a uniform format suitable for graph construction:
Construct a NetworkX directed graph from the normalized transaction data. Each node is an address, each directed edge is a transaction with amount, hash, and timestamp as edge attributes.
import networkx as nx
from typing import Optional
def build_tx_graph(df: pd.DataFrame) -> nx.DiGraph:
"""Build a directed transaction graph from normalized transaction data.
Edges: from → to, attributes include value_eth, hash, timestamp, token_symbol.
Self-loops (from == to) are excluded.
"""
G = nx.DiGraph()
for _, row in df.iterrows():
src = str(row.get("from", "")).lower()
dst = str(row.get("to", "")).lower()
if not src or not dst or src == dst:
continue
val = row.get("value_eth", 0) or row.get("value_token", 0) or 0
G.add_edge(src, dst, **{
"hash": row.get("hash", ""),
"value": float(val),
"timestamp": int(row.get("timestamp", 0)),
"token": row.get("token_symbol", "ETH"),
})
return G
def graph_summary(G: nx.DiGraph) -> dict:
"""Return summary statistics for a transaction graph."""
return {
"nodes": G.number_of_nodes(),
"edges": G.number_of_edges(),
"total_volume": sum(d["value"] for _, _, d in G.edges(data=True)),
"unique_sources": sum(1 for n, d in G.in_degree() if d == 0),
"unique_sinks": sum(1 for n, d in G.out_degree() if d == 0),
"density": nx.density(G),
}
def filter_by_value(G: nx.DiGraph, min_value: float = 0.01) -> nx.DiGraph:
"""Return a subgraph containing only edges above a minimum value threshold."""
edges_to_keep = [(u, v, d) for u, v, d in G.edges(data=True)
if d.get("value", 0) >= min_value]
H = nx.DiGraph()
H.add_edges_from(edges_to_keep)
return H
Step 4: Export Graph to DOT and GraphML
Generate visualization-ready graph formats for use with Graphviz and analysis tools:
def export_dot(G: nx.DiGraph, path: str = "tx_graph.dot") -> str:
"""Export the transaction graph as a DOT file for Graphviz rendering."""
# Relabel nodes to quoted strings for DOT compatibility
H = nx.DiGraph()
for u, v, d in G.edges(data=True):
label = f"{d.get('value', 0):.4f} {d.get('token', 'ETH')}"
H.add_edge(f'"{u[:10]}…"', f'"{v[:10]}…"', label=label)
nx.nx_pydot.write_dot(H, path)
return path
def export_graphml(G: nx.DiGraph, path: str = "tx_graph.graphml") -> str:
"""Export the transaction graph as GraphML for Gephi or yEd."""
nx.write_graphml(G, path)
return path
Step 5: Compute Graph Centrality and Find Key Nodes
Identify the most important addresses in the flow — the sink where funds concentrate, the original source, and intermediary hubs:
def find_source_nodes(G: nx.DiGraph) -> list[str]:
"""Return nodes with zero in-degree (original sources of funds)."""
return [n for n, d in G.in_degree() if d == 0]
def find_sink_nodes(G: nx.DiGraph) -> list[str]:
"""Return nodes with zero out-degree (endpoints — mixers, exchanges, bridges)."""
return [n for n, d in G.out_degree() if d == 0]
def rank_by_centrality(G: nx.DiGraph, top_n: int = 10) -> pd.DataFrame:
"""Rank addresses by weighted betweenness centrality.
Higher centrality means the address sits on more fund flow paths.
"""
if G.number_of_nodes() < 2:
return pd.DataFrame()
# Use edge weight (value) to weight paths
weight_attr = "value"
try:
centrality = nx.betweenness_centrality(G, weight=weight_attr)
except Exception:
centrality = nx.betweenness_centrality(G)
ranked = sorted(centrality.items(), key=lambda x: -x[1])
return pd.DataFrame(ranked[:top_n], columns=["address", "centrality"])
def find_top_volume_hubs(G: nx.DiGraph, top_n: int = 10) -> pd.DataFrame:
"""Find addresses with the highest total transaction volume (in + out)."""
volume = {}
for u, v, d in G.edges(data=True):
val = d.get("value", 0)
volume[u] = volume.get(u, 0) + val
volume[v] = volume.get(v, 0) + val
ranked = sorted(volume.items(), key=lambda x: -x[1])
return pd.DataFrame(ranked[:top_n], columns=["address", "total_value"])
Peel Chain Detection Algorithm
A peel chain is a money-laundering pattern where a large amount of cryptocurrency is split into gradually smaller amounts through a chain of addresses, obscuring the trail. Each address in the chain typically passes most of the funds forward while peeling off a small amount.
def detect_peel_chains(G: nx.DiGraph, max_path_length: int = 20,
min_hops: int = 3, value_decay_threshold: float = 0.95) -> list[dict]:
"""Detect peel chain patterns in a transaction graph.
A peel chain is a path where each hop passes most of the value forward
(value_decay_threshold controls how much value must be passed), with
small amounts peeled off along the way. Returns list of detected chains.
"""
chains = []
sources = find_source_nodes(G)
for src in sources:
visited = set()
path = []
current = src
while current and len(path) < max_path_length:
visited.add(current)
out_edges = list(G.out_edges(current, data=True))
if not out_edges:
break
# Sort outgoing edges by value descending
out_edges.sort(key=lambda e: e[2].get("value", 0), reverse=True)
best = out_edges[0]
next_addr = best[1]
val = best[2].get("value", 0)
# Check: does this edge pass most of the known incoming value?
in_edges = list(G.in_edges(current, data=True))
total_in = sum(e[2].get("value", 0) for e in in_edges)
if total_in > 0 and val / total_in < (1 - value_decay_threshold):
# This hop peeled off too much — likely a consolidation, not a peel chain
pass
path.append({
"from": current,
"to": next_addr,
"value": val,
"hash": best[2].get("hash", ""),
})
if next_addr in visited:
break
current = next_addr
if len(path) >= min_hops:
chains.append({
"start": src,
"end": current,
"hops": len(path),
"total_volume": sum(h["value"] for h in path),
"path": path,
})
return chains
def detect_peel_chain_heuristic_simple(address: str, txs: list[dict],
threshold_ratio: float = 0.8) -> list[dict]:
"""Detect peel chains using a simplified heuristic on raw transaction data.
A peel chain address sends most of its incoming value to a single output,
suggesting gradual fund distribution. This works on individual address analysis
without needing a full graph.
"""
outgoing = {}
for tx in txs:
frm = tx.get("from", "").lower()
to = tx.get("to", "").lower()
val = int(tx.get("value", 0))
if frm == address:
outgoing[to] = outgoing.get(to, 0) + val
if not outgoing:
return []
total_out = sum(outgoing.values())
chains = []
for dst, val in sorted(outgoing.items(), key=lambda x: -x[1]):
ratio = val / total_out if total_out > 0 else 0
if ratio >= threshold_ratio:
chains.append({
"from": address,
"to": dst,
"value": val,
"ratio": round(ratio, 4),
"pattern": "peel_chain_hop",
})
return chains
Consolidation Pattern Detector
Consolidation is the opposite of a peel chain — multiple addresses send funds to a single address. This is typical before an exchange deposit or when a hacker collects funds spread across many wallets.
def detect_consolidation(G: nx.DiGraph, min_sources: int = 3,
time_window_hours: int = 24) -> list[dict]:
"""Detect consolidation patterns in the transaction graph.
A consolidation is a node with N incoming edges from distinct addresses
within a time window. This is a classic exchange deposit / fund collection pattern.
"""
consolidations = []
for node in G.nodes():
in_edges = list(G.in_edges(node, data=True))
if len(in_edges) < min_sources:
continue
unique_sources = set(e[0] for e in in_edges)
if len(unique_sources) < min_sources:
continue
# Check time window
timestamps = [e[2].get("timestamp", 0) for e in in_edges]
timestamps = [t for t in timestamps if t > 0]
if timestamps:
span_hours = (max(timestamps) - min(timestamps)) / 3600
if span_hours > time_window_hours:
continue
total_value = sum(e[2].get("value", 0) for e in in_edges)
consolidations.append({
"sink": node,
"sources": list(unique_sources),
"num_sources": len(unique_sources),
"total_value": total_value,
"time_window_hours": round(span_hours, 2) if timestamps else 0,
"tx_hashes": [e[2].get("hash", "") for e in in_edges],
})
return sorted(consolidations, key=lambda c: -c["num_sources"])
def detect_consolidation_simple(txs: list[dict], min_sources: int = 5) -> list[dict]:
"""Detect consolidation by checking which addresses receive from many distinct senders.
Works on raw transaction data without a full graph.
"""
from collections import Counter
receivers = Counter()
receiver_txs = {}
for tx in txs:
to = tx.get("to", "").lower()
frm = tx.get("from", "").lower()
if to and frm:
receivers[to] += 1
if to not in receiver_txs:
receiver_txs[to] = []
receiver_txs[to].append(tx)
consolidations = []
for addr, count in receivers.most_common():
if count >= min_sources:
total_val = sum(int(tx.get("value", 0)) for tx in receiver_txs[addr])
consolidations.append({
"address": addr,
"incoming_count": count,
"total_value": total_val,
"source_addresses": list(set(
tx.get("from", "").lower() for tx in receiver_txs[addr]
)),
})
return consolidations
Mixer Identification
Known Mixer/Sanitizer Contract Addresses
Service
Chain
Address
Type
Notes
Tornado Cash
Ethereum
0x12d66f87a04a9e220743712ce6d9bb1b5616b8fc
ETH mixer
0.1 ETH pool
Tornado Cash
Ethereum
0x47ce0c6ed5b0ce3d3a51fdb1c52dc66a7c3c2936
ETH mixer
1 ETH pool
Tornado Cash
Ethereum
0x910cbd523d972eb0a6f4cae4618ad62622b39dbf
ETH mixer
10 ETH pool
Tornado Cash
Ethereum
0xa160cdab2250da5b3f80029b6b82e1d5d0c30efb
ETH mixer
100 ETH pool
Tornado Cash
BSC
0x1e34a77868e19a6647b1f2f47b51ed72dede95dd
BNB mixer
100 BNB pool
Tornado Cash
Polygon
0x47ce0c6ed5b0ce3d3a51fdb1c52dc66a7c3c2936
MATIC mixer
1000 MATIC pool
Sinbad
Ethereum
0x1e31cb9b6b69a7df3225220a0ef1f0a76586d5a3
ETH mixer
Sinbad
Ethereum
0x8589427373d6d84e98730d7795d8f6f8731fda16
ETH mixer
Wasabi Wallet
Bitcoin
bc1q… (varies)
BTC CoinJoin
Uses PayNym, no fixed address
Samourai Whirlpool
Bitcoin
(Coordinator)
BTC CoinJoin
No fixed deposit address
ChainFlip
Ethereum
0x60fB0B27447480E3304bB7b2660e9C081D3775fc
Cross-chain mixer
eXch
Ethereum
(varies)
Swap-based mixer
Swaps and splits
FixedFloat
Multi
(varies)
Swap-based mixer
No-KYC exchange used for obfuscation
Mixer Deposit Detection Heuristics
# Known mixer contract addresses (Ethereum mainnet)
MIXER_ADDRESSES = {
# Tornado Cash deposit addresses (by pool size)
"0x12d66f87a04a9e220743712ce6d9bb1b5616b8fc": "tornado_0.1_eth",
"0x47ce0c6ed5b0ce3d3a51fdb1c52dc66a7c3c2936": "tornado_1_eth",
"0x910cbd523d972eb0a6f4cae4618ad62622b39dbf": "tornado_10_eth",
"0xa160cdab2250da5b3f80029b6b82e1d5d0c30efb": "tornado_100_eth",
# Sinbad
"0x1e31cb9b6b69a7df3225220a0ef1f0a76586d5a3": "sinbad_1",
"0x8589427373d6d84e98730d7795d8f6f8731fda16": "sinbad_2",
}
def tag_mixer_interactions(df: pd.DataFrame) -> pd.DataFrame:
"""Tag transactions involving known mixer addresses."""
df_lower = df.copy()
df_lower["to"] = df_lower["to"].str.lower()
df_lower["from"] = df_lower["from"].str.lower()
df_lower["mixer"] = "unknown"
for addr, name in MIXER_ADDRESSES.items():
mask = (df_lower["to"] == addr) | (df_lower["from"] == addr)
df_lower.loc[mask, "mixer"] = name
return df_lower
def detect_mixer_deposit_by_amount(address: str, txs: list[dict],
known_amounts: list[float] = None) -> bool:
"""Detect potential mixer deposits by checking for exact-amount patterns.
Mixers use fixed deposit amounts (e.g., Tornado Cash pools).
If an address sends an exact pool amount to a contract, it's likely a mixer deposit.
"""
if known_amounts is None:
known_amounts = [0.1, 1.0, 10.0, 100.0] # Tornado Cash standard pool amounts
for tx in txs:
frm = tx.get("from", "").lower()
val_eth = int(tx.get("value", 0)) / 1e18
if frm == address.lower() and val_eth in known_amounts:
# Verify the recipient has contract code (mixer contract, not EOA)
return True
return False
def detect_mixer_timing_anomaly(txs: list[dict], time_window_minutes: int = 30) -> list[dict]:
"""Detect mixer deposit patterns by timing.
Mixer deposits often cluster in tight time windows.
Multiple deposits to different addresses from the same source within a short window
is a strong mixer indicator.
"""
from collections import defaultdict
windows = defaultdict(list)
for tx in txs:
ts = int(tx.get("timeStamp", 0))
to = tx.get("to", "").lower()
if ts:
bucket_key = ts // (time_window_minutes * 60) # bucket by time window
windows[bucket_key].append(tx)
suspicious = []
for bucket, group in windows.items():
unique_recipients = set(t.get("to", "").lower() for t in group)
if len(unique_recipients) >= 3:
total_val = sum(int(t.get("value", 0)) for t in group) / 1e18
suspicious.append({
"time_bucket": bucket,
"num_txs": len(group),
"unique_recipients": len(unique_recipients),
"total_value_eth": total_val,
"txs": [t.get("hash", "") for t in group[:10]],
})
return suspicious
Cross-Chain Bridge Tracing
Bridges are the most common obfuscation technique post-hack. The attacker deposits on Chain A and withdraws on Chain B, often swapping the asset type.
Known Bridge Contract Addresses
Bridge
Chain
Contract Address
Event Signature
LayerZero Endpoint
Ethereum
0x66A71Dcef29A0fFBDBE3c6a460a3B5BC225Cd675
MessagePayload
Stargate Router
Ethereum
0x8731d54E9D02c286767d56ac03e8037C07e01e98
Swap
Stargate Router
Arbitrum
0x53Bf833A5d6c4ddA888F69c22C88C9f356a41614
Swap
Wormhole Core
Ethereum
0x98f3c9e6E3fAce36bAAd05FE09d375Ef1464288B
LogMessagePublished
Wormhole Token Bridge
Ethereum
0x3ee18B2214AFF97000D974cf647E7C347E8fa585
TransferRedeemed
Across
Ethereum
0x5c7BCd6E7De5423a257D81B442095A1a6ced35C5
FundsDeposited
Across
Arbitrum
0x3bB4445D30AC020a84c1b5A8A2C6248ebC9779D0
FundsDeposited
Synapse
Ethereum
0x2796317b0fF8538F253012862c06787Adfb8c3aC
TokenDeposit
Synapse
Arbitrum
0x9D33eeE1540BdA15C2021C22E14dfdB41c58485b
TokenDeposit
Hop
Ethereum
0x3666f603Cc164936C1b87e207F36BEBa4AC5f18a
TransferSent
Hop
Polygon
0x3666f603Cc164936C1b87e207F36BEBa4AC5f18a
TransferSent
AnySwap (Multichain)
Ethereum
0x6b7a87899490EcE95443e979cA9485CBE7E71522
AnySwapOut
Celer cBridge
Ethereum
0x1619DE6B6B20eD217a58d00f37B9d47C7663feca
Send
Bridge Detection Code
BRIDGE_CONTRACTS = {
"layerzero_endpoint": {
"ethereum": ["0x66a71dcef29a0ffbdbe3c6a460a3b5bc225cd675"],
"arbitrum": ["0x3c2269811836af69497e5f486a85d7316753cf02"],
"polygon": ["0x3c2269811836af69497e5f486a85d7316753cf02"],
},
"stargate_router": {
"ethereum": ["0x8731d54e9d02c286767d56ac03e8037c07e01e98"],
"arbitrum": ["0x53bf833a5d6c4dda888f69c22c88c9f356a41614"],
"polygon": ["0x53bf833a5d6c4dda888f69c22c88c9f356a41614"],
},
"across": {
"ethereum": ["0x5c7bcd6e7de5423a257d81b442095a1a6ced35c5"],
"arbitrum": ["0x3bb4445d30ac020a84c1b5a8a2c6248ebc9779d0"],
},
"synapse": {
"ethereum": ["0x2796317b0ff8538f253012862c06787adfb8c3ac"],
"arbitrum": ["0x9d33eee1540bda15c2021c22e14dfdb41c58485b"],
},
"wormhole": {
"ethereum": ["0x98f3c9e6e3face36baad05fe09d375ef1464288b"],
},
"hop": {
"ethereum": ["0x3666f603cc164936c1b87e207f36beba4ac5f18a"],
"polygon": ["0x3666f603cc164936c1b87e207f36beba4ac5f18a"],
},
"celer": {
"ethereum": ["0x1619de6b6b20ed217a58d00f37b9d47c7663feca"],
},
}
# Flatten bridge addresses to a single set for fast lookup
ALL_BRIDGE_ADDRESSES = set()
for name, chains in BRIDGE_CONTRACTS.items():
for chain_addrs in chains.values():
ALL_BRIDGE_ADDRESSES.update(chain_addrs)
def tag_bridge_interactions(df: pd.DataFrame) -> pd.DataFrame:
"""Tag transactions involving known bridge contracts."""
df_lower = df.copy()
for col in ["to", "from"]:
df_lower[col] = df_lower[col].str.lower()
def lookup(addr):
addr = addr.lower()
for name, chains in BRIDGE_CONTRACTS.items():
for chain_addrs in chains.values():
if addr in chain_addrs:
return name
return ""
df_lower["bridge"] = df_lower["to"].apply(lookup)
# Also check 'from' field for bridge interactions
mask_from = df_lower["bridge"] == ""
df_lower.loc[mask_from, "bridge"] = df_lower.loc[mask_from, "from"].apply(lookup)
return df_lower
def detect_bridge_transfer(tx: dict, receipt_logs: list[dict]) -> dict:
"""Detect bridge transfer from a transaction's event logs.
Returns destination chain info if a bridge event is found.
"""
for log in receipt_logs:
addr = log.get("address", "").lower()
topics = log.get("topics", [])
# Stargate Swap event: topics[0] = Swap(uint16,uint16,address,address,uint256,uint256)
if addr in ALL_BRIDGE_ADDRESSES and len(topics) >= 3:
return {
"bridge_detected": True,
"contract": addr,
"tx_hash": tx.get("hash", ""),
"topics": topics,
"data": log.get("data", ""),
"note": "Bridge interaction detected — check destination chain in event data",
}
return {"bridge_detected": False}
def extract_bridge_destination(tx_hash: str, web3_provider, bridge_address: str) -> int:
"""Extract destination chain ID from a Stargate bridge event.
Stargate emits Swap(uint16 chainIdFrom, uint16 chainIdTo, ...).
The chainIdTo is typically topic[2] in the Swap event.
"""
receipt = web3_provider.eth.get_transaction_receipt(tx_hash)
for log in receipt.logs:
if log.address.lower() == bridge_address.lower():
topics = log.topics
if len(topics) >= 3:
dest_chain_id = int.from_bytes(topics[2], "big")
return dest_chain_id
return 0
Wallet Clustering Implementation
CoJoin / Common-Input Clustering (UTXO Chains)
Bitcoin-like UTXO chains enable a powerful clustering heuristic: if two addresses appear as inputs in the same transaction, they are controlled by the same entity (assuming multi-signature or CoinJoin is not involved). This is called CoJoin or Common-Input-Ownership Heuristic.
def cluster_by_common_input(txs_utxo: list[dict]) -> dict[str, set[str]]:
"""Cluster Bitcoin addresses by common-input ownership heuristic.
If addresses A and B appear as inputs in the same transaction,
they are likely controlled by the same entity. Returns a dict
mapping cluster_id -> set of addresses.
"""
address_to_tx = {}
tx_to_addresses = {}
for tx in txs_utxo:
txid = tx.get("txid", "")
input_addresses = set()
for vin in tx.get("vin", []):
addr = vin.get("prevout", {}).get("scriptpubkey_address", "")
if addr:
input_addresses.add(addr)
if len(input_addresses) >= 2:
tx_to_addresses[txid] = input_addresses
for addr in input_addresses:
if addr not in address_to_tx:
address_to_tx[addr] = []
address_to_tx[addr].append(txid)
# Union-Find to merge clusters
parent = {}
def find(x):
while parent[x] != x:
parent[x] = parent[parent[x]]
x = parent[x]
return x
def union(a, b):
ra, rb = find(a), find(b)
if ra != rb:
parent[ra] = rb
all_addresses = set()
for addresses in tx_to_addresses.values():
addrs = list(addresses)
for addr in addrs:
if addr not in parent:
parent[addr] = addr
all_addresses.add(addr)
for i in range(1, len(addrs)):
union(addrs[0], addrs[i])
# Build clusters
clusters = {}
for addr in all_addresses:
root = find(addr)
if root not in clusters:
clusters[root] = set()
clusters[root].add(addr)
return clusters
def cluster_by_deposit_address(txs: list[dict], exchange_pattern: str = "binance") -> list[dict]:
"""Identify exchange deposit addresses by known patterns.
Many exchanges use deterministic deposit addresses.
This heuristic clusters addresses that receive from many senders
as potential exchange deposit addresses.
"""
from collections import Counter, defaultdict
deposits_to = Counter()
depositors = defaultdict(set)
for tx in txs:
to = tx.get("to", "").lower()
frm = tx.get("from", "").lower()
if to and frm:
deposits_to[to] += 1
depositors[to].add(frm)
clusters = []
for addr, count in deposits_to.most_common(50):
if count >= 10:
clusters.append({
"deposit_address": addr,
"incoming_count": count,
"unique_depositors": len(depositors[addr]),
"likely_entity": exchange_pattern if count > 50 else "unknown",
})
return clusters
EVM Address Reuse Clustering
Even on account-based chains, addresses can be clustered by behavioral patterns:
def cluster_by_behavior(df: pd.DataFrame, min_interactions: int = 5) -> dict[str, list[str]]:
"""Cluster EVM addresses by behavioral similarity.
If two addresses interact with the same set of contracts/protocols,
they may be controlled by the same entity.
"""
from collections import defaultdict
addr_contracts = defaultdict(set)
for _, row in df.iterrows():
frm = str(row.get("from", "")).lower()
to = str(row.get("to", "")).lower()
if frm and to:
addr_contracts[frm].add(to)
if to:
addr_contracts[to] # ensure key exists
# Jaccard similarity between address contract sets
addrs = list(addr_contracts.keys())
clusters = defaultdict(list)
assigned = set()
for i, a1 in enumerate(addrs):
if a1 in assigned:
continue
set1 = addr_contracts[a1]
if len(set1) < min_interactions:
continue
cluster = [a1]
assigned.add(a1)
for a2 in addrs[i + 1:]:
if a2 in assigned:
continue
set2 = addr_contracts[a2]
if len(set2) < min_interactions:
continue
intersection = len(set1 & set2)
union = len(set1 | set2)
if union > 0 and intersection / union >= 0.7:
cluster.append(a2)
assigned.add(a2)
if len(cluster) >= 2:
clusters[f"behavioral_cluster_{len(clusters)}"] = cluster
return clusters
Sankey / Flow Diagram Visualization
Generate an interactive HTML flow visualization using Plotly. This produces a browser-ready trace report.
import plotly.graph_objects as go
from typing import Optional
def build_sankey_diagram(G: nx.DiGraph, title: str = "Transaction Flow",
max_nodes: int = 50, min_value: float = 0.01,
output_path: Optional[str] = "tx_flow.html") -> Optional[str]:
"""Generate an interactive Sankey diagram from the transaction graph.
Nodes are addresses, link thickness represents transaction value.
Only the top-max_nodes by volume are included for readability.
"""
# Filter by value and take top nodes
H = filter_by_value(G, min_value)
# Compute total flow per node and keep top
node_volume = {}
for u, v, d in H.edges(data=True):
val = d.get("value", 0)
node_volume[u] = node_volume.get(u, 0) + val
node_volume[v] = node_volume.get(v, 0) + val
top_nodes = set(sorted(node_volume, key=node_volume.get, reverse=True)[:max_nodes])
H = H.subgraph(top_nodes)
# Map addresses to labels
nodes = list(H.nodes())
node_map = {n: i for i, n in enumerate(nodes)}
labels = [f"{n[:6]}…{n[-4:]}" for n in nodes]
# Build Sankey links
sources, targets, values, hover_texts = [], [], [], []
for u, v, d in H.edges(data=True):
sources.append(node_map[u])
targets.append(node_map[v])
val = d.get("value", 0)
values.append(max(val * 100, 1)) # Scale for visibility
h = d.get("hash", "")[:10]
ts = d.get("timestamp", 0)
token = d.get("token", "ETH")
hover_texts.append(
f"From: {u[:6]}…{u[-4:]}<br>"
f"To: {v[:6]}…{v[-4:]}<br>"
f"Value: {val:.4f} {token}<br>"
f"Tx: {h}…<br>"
f"Timestamp: {ts}"
)
fig = go.Figure(data=[go.Sankey(
node=dict(
pad=15,
thickness=20,
line=dict(color="black", width=0.5),
label=labels,
color="blue",
),
link=dict(
source=sources,
target=targets,
value=values,
hovertext=hover_texts,
hoverinfo="text",
)
)])
fig.update_layout(title=title, font_size=12, height=800)
if output_path:
fig.write_html(output_path)
return output_path
def build_consolidation_sankey(clusters: list[dict], output_path: str = "consolidation.html") -> str:
"""Generate a Sankey diagram focused on consolidation patterns.
Shows multiple source addresses flowing into each sink.
"""
sources, targets, values, hover_texts = [], [], [], []
labels = []
idx = 0
for cluster in clusters[:20]: # Limit to top 20 clusters
sink = cluster.get("sink", cluster.get("address", ""))
if sink not in labels:
labels.append(sink)
sink_idx = len(labels) - 1
else:
sink_idx = labels.index(sink)
for src in cluster.get("sources", [])[:10]: # Limit to 10 sources per sink
if src not in labels:
labels.append(src)
src_idx = len(labels) - 1
else:
src_idx = labels.index(src)
sources.append(src_idx)
targets.append(sink_idx)
values.append(5) # Uniform thickness
hover_texts.append(f"{src[:6]}…→ {sink[:6]}…")
fig = go.Figure(data=[go.Sankey(
node=dict(pad=15, thickness=20, line=dict(color="black", width=0.5),
label=[f"{l[:6]}…{l[-4:]}" for l in labels]),
link=dict(source=sources, target=targets, value=values,
hovertext=hover_texts, hoverinfo="text"),
)])
fig.update_layout(title="Consolidation Patterns", height=600)
fig.write_html(output_path)
return output_path
Case Study: Tracing a Simulated Bridge Hack Fund Flow
This scenario demonstrates a realistic theft investigation. Adapt the addresses and step sequence to your actual case.
Scenario: The XYZ Bridge was exploited for 5,000 ETH on Ethereum mainnet. The attacker address is 0xAttackerXYZ....
# === PHASE 1: Initial Theft ===
# The attacker drained 5,000 ETH from the bridge contract on Ethereum.
# Target address: 0xAttackerXYZ (replace with actual address)
api_key = "YOUR_ETHERSCAN_API_KEY"
# Step A: Collect all transaction data from the attacker address
attacker_txs = collect_all_txs("0xAttackerXYZ...", api_key, chain_id=1)
df_attacker = normalize_txs(attacker_txs["normal"])
df_attacker_internal = normalize_txs(attacker_txs["internal"])
df_attacker_erc20 = normalize_txs(attacker_txs["erc20"], tx_type="erc20")
# Combine all transactions
df_all = pd.concat([df_attacker, df_attacker_internal, df_attacker_erc20],
ignore_index=True)
print(f"Collected {len(df_all)} transactions for attacker address")
# Step B: Build the transaction graph
G = build_tx_graph(df_all)
summary = graph_summary(G)
print(f"Graph: {summary['nodes']} nodes, {summary['edges']} edges")
# Step C: Find the first outgoing transaction (likely proceeds movement)
first_out = df_all[df_all["from"] == "0xattackerxyz..."] \
.sort_values("timestamp").head(5)
print("First outgoing transactions from attacker:")
print(first_out[["hash", "to", "value_eth", "timestamp"]].to_string())
# === PHASE 2: Follow the Money ===
# The attacker split the funds across multiple addresses (peel chain).
peel_chains = detect_peel_chains(G, min_hops=3)
print(f"Detected {len(peel_chains)} potential peel chains")
for chain in peel_chains:
print(f" Peel chain: {chain['start']} → {chain['end']} "
f"({chain['hops']} hops, {chain['total_volume']:.2f} ETH)")
# === PHASE 3: Identify Mixer Deposits ===
# Check if any trace deposits to Tornado Cash
df_tagged = tag_mixer_interactions(df_all)
mixer_txs = df_tagged[df_tagged["mixer"] != "unknown"]
print(f"\nMixer interactions: {len(mixer_txs)}")
for _, tx in mixer_txs.iterrows():
print(f" {tx['hash']}: → {tx['to']} ({tx['mixer']}) "
f"value={tx['value_eth']:.4f} ETH")
# === PHASE 4: Bridge to Another Chain ===
# Check if the attacker used a bridge
df_bridge = tag_bridge_interactions(df_all)
bridge_txs = df_bridge[df_bridge["bridge"] != ""]
print(f"\nBridge interactions: {len(bridge_txs)}")
for _, tx in bridge_txs.iterrows():
print(f" {tx['hash']}: → {tx['to']} (bridge={tx['bridge']}) "
f"value={tx['value_eth']:.4f} ETH")
# === PHASE 5: Detect Consolidation ===
# Eventually, funds consolidate before an exchange deposit
consolidations = detect_consolidation(G, min_sources=3)
print(f"\nConsolidation patterns: {len(consolidations)}")
for c in consolidations[:5]:
print(f" Sink: {c['sink'][:10]}... "
f"Sources: {c['num_sources']} "
f"Value: {c['total_value']:.2f} ETH")
# === PHASE 6: Generate Sankey Visualization ===
build_sankey_diagram(G, title="Bridge Hack Fund Flow",
max_nodes=40, min_value=0.1,
output_path="bridge_hack_trace.html")
print("\nFlow diagram generated: bridge_hack_trace.html")
# === PHASE 7: Export Graph for Analysis ===
export_dot(G, "bridge_hack_trace.dot")
export_graphml(G, "bridge_hack_trace.graphml")
print("Graph exported to DOT and GraphML formats")
Expected trace result for this scenario:
0xAttackerXYZ → receives 5,000 ETH from bridge drain
Splits into 5 x 1,000 ETH transfers to intermediate wallets (peel chain hop 1)
Each intermediate sends ∼997 ETH to Tornado Cash 1,000 ETH pool (mixer deposit)
Small amount (∼3 ETH) moves to another peel chain layer
After mixing: funds emerge on Arbitrum via LayerZero bridge
Complete forensic report with all algorithms (peel chain, consolidation, mixer, bridge detection), interactive flow HTML, raw data exports, expert affidavit
Dashboard with real-time graph updates, API access, weekly briefings
$10,000 – $50,000/month
Law Enforcement / Legal Consulting Rates
Service
Rate
Expert witness testimony (deposition)
$500 – $1,000/hour
Expert witness testimony (trial)
$1,000 – $3,000/hour
Forensic report for litigation
$5,000 – $25,000 flat
Case consultation (hourly)
$300 – $500/hour
Bounty Hunting Revenue
Platform
Typical Payout
Notes
Arkham Intelligence
$500 – $50,000+ per bounty
Requires verified wallet attribution
Lazarus Bounty
Up to 10% of recoverable funds
Focused on North Korean hacker wallets
Immunefi (trace required)
Part of larger bug bounty
Trace + smart contract audit combined
HackerOne/ Bugcrowd
Variable
Some programs pay for fund flow analysis
Private crypto investigation firms
Contract rates
Chainalysis, TRM Labs, CipherTrace partners
Business Models
Per-report consulting: Charge per trace report for incident victims. Most crypto thefts >$100K have victims willing to pay $2K-$10K for a professional trace.
Subscription monitoring: Recurring fee for wallet/address monitoring with alerts on fund movement. Target: DeFi protocols, VCs, high-net-worth individuals.
Bounty hunting: Register on Arkham, Lazarus Bounty, and Immunefi. Spend 20-40 hours per lead. Hit rate varies but single bounties can exceed $50K.
Expert witness: Build relationships with law firms handling crypto fraud and bankruptcy cases. Bill at $500-$3K/hour.
Training/education: Sell courses on blockchain forensics. Pre-recorded course $500-$2K per student. Corporate training $5K-$20K per session.
Tool licensing: Build a SaaS tool wrapping these algorithms. $50-$500/month per user.
Expected Output
A forensic trace report containing:
Transaction flow graph (interactive HTML Sankey diagram + DOT/GraphML format)
Raw data exports (CSV, GraphML) for independent verification
For legal use: expert affidavit summarizing methodology and findings
Red Flags
Attempting to deanonymize addresses without proper authorization or legal basis
Drawing conclusions from incomplete data (missing internal transactions or token transfers)
Over-relying on a single block explorer that may have incomplete indexing
Assuming a wallet belongs to an entity without cross-referencing multiple data sources
Treating change addresses (UTXO) as separate entities from the spending wallet
Ignoring transaction fees in value calculations — they affect net amounts in peel chains
Conflating internal transactions (contract CALLs) with external ETH transfers
Assuming a CoinJoin transaction implies address clustering — it's designed to break this heuristic
Trusting a single API response without retrying on rate-limit errors (429 responses)
Failing to account for wrapped assets (wETH, wBTC) as equivalent to the underlying asset
Process
Data Collection — Gather all transaction data for target addresses from block explorers and RPC nodes. Use pagination for high-volume addresses. Collect normal, internal, and token transfers for EVM chains; UTXO inputs/outputs for Bitcoin.
Flow Mapping — Build a directed transaction graph using NetworkX. Apply filtering thresholds to remove dust transactions. Compute graph statistics (source/sink nodes, centrality, volume hubs).
Pattern Detection — Run peel chain detection, consolidation detection, mixer identification, and bridge extraction algorithms. Each pattern provides labeled subgraphs for the investigator.
Entity Attribution — Cross-reference addresses against known entity databases (mixer addresses table, bridge contracts table, known exchange wallets). Tag each node with its likely entity type.
Clustering — Apply CoJoin clustering for UTXO addresses, behavioral similarity clustering for EVM addresses. Merge clusters into entity-level groups.
Cross-Chain Tracking — Follow funds through bridges by scanning interaction with known bridge contracts. Extract destination chain IDs from bridge event logs. Re-query the destination chain with the output address.
Visualization — Generate Sankey flow diagrams and DOT/GraphML exports. Produce both summary view (all hops) and filtered view (significant transfers only).
Reporting — Produce structured trace report with flow diagrams, confidence scores, endpoint identification, and raw data exports.
Verification
Every trace hop verified against the source block explorer (not just API data)
Transaction hashes cross-referenced on at least two independent explorers where possible
Entity attributions confirmed by multiple data points, not single-source assumptions
Graph visualization matches the raw transaction data (no skipped or double-counted hops)
Internal transaction values summed and cross-checked against normal transaction balances
Bridge event logs parsed and verified for correct destination chain ID
NetworkX graph edge count matches the number of filtered transactions
USD value conversions use historical price data (CoinGecko or similar) at the block timestamp
Sankey diagram total inflow matches total outflow (conservation of value)
Report includes raw data exports so findings can be independently verified
RPC & API Endpoint Management
Multi-Provider Fallback Strategy
import os, time, requests
BLOCK_EXPLORERS = {
"ethereum": [{"name": "etherscan", "base": "https://api.etherscan.io/api", "key_env": "ETHERSCAN_API_KEY"},
{"name": "etherscan-2","base": "https://api.etherscan.io/api", "key_env": "ETHERSCAN_API_KEY_2"}],
"bsc": [{"name": "bscscan", "base": "https://api.bscscan.com/api", "key_env": "BSCSCAN_API_KEY"}],
"polygon": [{"name": "polygonscan","base": "https://api.polygonscan.com/api", "key_env": "POLYGONSCAN_API_KEY"}],
}
def robust_explorer_call(chain: str, params: dict, retries: int = 3) -> dict | None:
"""Call block explorer API with per-chain fallback and rate-limit backoff."""
providers = BLOCK_EXPLORERS.get(chain, [])
for provider in providers:
api_key = os.environ.get(provider["key_env"])
if not api_key:
continue
params["apikey"] = api_key
for attempt in range(retries):
try:
resp = requests.get(provider["base"], params=params, timeout=30)
data = resp.json()
if data.get("status") == "1":
return data
if "rate limit" in str(data).lower():
time.sleep(2 ** attempt) # exponential backoff
continue
return data # non-rate-limit error, return anyway
except (requests.ConnectionError, requests.Timeout):
time.sleep(2 ** attempt)
return None
Key Hygiene
Store keys in .env with per-chain names (ETHERSCAN_API_KEY, BSCSCAN_API_KEY).
Add a second Etherscan key (ETHERSCAN_API_KEY_2) for high-volume traces — the rate limit is per-key.
No key? Use the Covalent free tier (1 key, 30+ chains, 5 req/s) or the block explorer web UI (curl-able, no key for individual lookups).
When the Trace Goes Cold
Common Dead Ends and Real Resolutions
On-Chain Signal
Interpretation
Action
Funds hit a CEX deposit address
Last on-chain point — exchange owns the address
Document tx hash + timestamp. This is a subpoena/subpoena-ready endpoint.
Funds enter a privacy mixer (Tornado Cash, RAILGUN)
Intentional obfuscation
Record deposit amount + block. Scan ±200 blocks for matching withdrawal amounts.
Transaction is a create2 deployment
Counterfactual contract — may not exist yet
Compute predicted address from deployer + salt. Monitor for creation tx.
Target address has zero outgoing txs for 72h+
Sleeping address or intentional hold
Set up a cron job (crontab -e, check every 6h via txlist) to detect future movement.
Funds bridged to another chain
Cross-chain escape
Parse the Transfer/Swap event on the source bridge contract. Extract destinationChainId and receiver. Re-query on the target chain.
Contract self-destructed
Intentional state destruction
Investigate deployer address. The SELFDESTRUCT opcode sends remaining ETH to a target — follow that.
UTXO chain — single input, single output
Normal spend
Check for address reuse patterns; if none, this branch is cold.
The 10/3 Rule
If you have made 10 API lookups on a single address and found 0 new leads in the last 3, stop. Archive the investigation with:
def archive_cold_trail(address: str, chain: str, last_tx: str, notes: str):
"""Log a cold trail for periodic re-check."""
record = {"address": address, "chain": chain, "last_tx_hash": last_tx,
"archived_at": time.time(), "notes": notes, "next_check": time.time() + 604800}
# Append to cold_trails.jsonl — re-check weekly
with open("cold_trails.jsonl", "a") as f:
f.write(json.dumps(record) + "\n")
Do not delete cold trails. The trace is not dead — it's waiting for the next transaction that hasn't happened. Archive with a weekly re-check window and move to higher-signal addresses.
Practices from Top Investigators
The ZachXBT Methodology
ZachXBT is the most recognized on-chain investigator, having traced over $243M in stolen crypto
funds. His methodology combines on-chain analysis with extensive cross-platform OSINT, turning
blockchain pseudonymity into identity evidence. This section codifies his proven techniques.
The 12-Tool Arsenal
Tool
Purpose
When to Use
Etherscan / Solscan
Primary chain explorer (tx list, internal txs, token transfers)
Every trace — start here
Arkham Intelligence
Visual fund flow graphs, entity tags, exchange hot wallets
Mid-trace: visualize complex hop chains
MetaSleuth
Cross-chain fund flow visualization with one-click explorer links
When traces span 3+ chains
Cielo
Real-time wallet monitoring, push alerts on target addresses
After identifying key addresses — set alerts before sleeping
Cross-chain portfolio view — balance history over time
Quick assessment of a wallet's activity pattern
OKLink
Multi-chain explorer with cross-chain bridge tracking
Following funds across L1s and L2s
OMNIA
Mempool monitoring, pending tx capture
Catching transactions before they confirm
MetaSuites
Batch address lookups, legacy labeling data
De-anonymizing old addresses with pre-2020 data
Funding Chain Tracing (His Signature Method)
The core insight: trace the attacker's funding, not just the stolen funds. Attackers almost
always fund their operations from an earlier hack or a tied wallet. Tracing backward from the
attack transaction to the original source of the ETH used for gas fees often reveals:
The same attacker's previous hacks (same funding source → same person)
Exchange deposit patterns that reveal identity
Timing links between multiple attacks
def trace_funding_chain(attacker_address: str, chain: str = "ethereum") -> list[dict]:
"""Trace attacker's funding chain backward from attack tx.
ZachXBT technique: find where the ATTACKER got their gas money.
The funding source often ties multiple hacks to the same person.
"""
from etherscan_v2_api import fetch_txlist, fetch_internal_txlist
from collections import deque
visited = {attacker_address}
queue = deque([attacker_address])
funding_chain = []
max_depth = 5 # attackers rarely fund more than 5 hops deep
while queue and len(funding_chain) < max_depth:
addr = queue.popleft()
# Get the FIRST transaction the address ever received (its funding)
txs = fetch_txlist(addr, chain, sort="asc", limit=1) or []
internal_txs = fetch_internal_txlist(addr, chain, sort="asc", limit=1) or []
earliest = (txs or internal_txs)[0] if (txs or internal_txs) else None
if not earliest:
funding_chain.append({"address": addr, "funding_source": "unknown", "depth": len(funding_chain)})
continue
sender = earliest.get("from", "")
funding_chain.append({
"address": addr,
"funded_by": sender,
"value_eth": earliest.get("value_eth", earliest.get("value", 0)),
"block": earliest.get("blockNumber"),
"tx_hash": earliest.get("hash") or earliest.get("transactionHash"),
})
if sender and sender not in visited:
visited.add(sender)
queue.append(sender)
# Check: do any funding sources overlap with known hacker addresses?
# This is the key pattern — same funder = same attacker across exploits
return funding_chain
Cross-Platform OSINT Integration
ZachXBT never stops at the blockchain. Every address is cross-referenced with:
ENS/Unstoppable Domains — Metadata that links to real-world identities
Forum posts (BitcoinTalk, Reddit) — Historical posts with wallet mentions
def cross_platform_lookup(address: str, identity_hints: dict[str, str] = None) -> dict:
"""Cross-reference an address across OSINT sources.
identity_hints: {"twitter": "handle", "github": "username", "ens": "name.eth"}
"""
results = {"address": address, "platforms": {}}
# 1. ENS reverse lookup
try:
resp = requests.get(f"https://api.ensideas.com/ens/resolve/{address}", timeout=10)
if resp.ok:
data = resp.json()
results["platforms"]["ens"] = {"name": data.get("ens"), "avatar": data.get("avatar")}
except Exception:
pass
# 2. Check known exploit databases for this address
try:
resp = requests.get(
"https://raw.githubusercontent.com/The-Blockchain-Repository/Hack-Transactions/main/data/latest.json",
timeout=10)
if resp.ok:
exploits = [e for e in resp.json() if address.lower() in str(e).lower()]
if exploits:
results["platforms"]["exploit_db"] = {"matches": len(exploits)}
except Exception:
pass
# 3. If we have social media hints, search for them (pseudocode — API keys vary)
if identity_hints:
results["platforms"]["hints_provided"] = identity_hints
results["note"] = "Cross-reference identity hints against on-chain activity timestamps"
return results
Address Cluster Publication
ZachXBT publicly releases address clusters on Twitter/X after investigations. This creates a
positive feedback loop: the community cross-references new scams against published clusters,
identifying repeat offenders across projects.
Publishing strategy:
Include all identified addresses (EOAs, contracts, intermediate wallets)
Label each address with its role (deployer, funder, intermediate, exchange deposit)
Chain + tx hash evidence for every link — no unsupported claims
Timestamp the publication to establish timeline priority
The Bounty Model
ZachXBT demonstrates that on-chain investigation is a viable career. Revenue sources:
Community-funded bounties — Twitter/X tip jar, Gitcoin grants, mirror.xyz articles
Exchange bug bounties — Exchanges pay for intelligence that helps them freeze stolen funds
Project recovery bounties — 5-15% of recovered funds for tracing assistance
Media consulting — Journalists pay for investigation reports on high-profile incidents
Private investigations — Law firms and insurance companies contract for court-ready reports
Anti-Rationalization Table
Anti-Rationalization Table
Rationalization
Reality
"Blockchain is anonymous so tracing is impossible"
Blockchain is pseudonymous, not anonymous. Every transaction is permanently recorded and analyzable.
"Mixers make tracing impossible"
Mixers complicate but don't prevent tracing. Timing analysis, amount patterns, and deposit/withdrawal correlations often deanonymize users.
"The amount is too small to trace"
Small amounts are often test transactions. Follow the same address for larger patterns — test txs confirm control.
"Cross-chain transactions break the trail"
Bridge contracts, wrapped assets, and event logs leave permanent on-chain evidence on both chains. The trail is cross-referencable.
"Peel chains are too complex to map"
Peel chains show a statistical signature (decaying value per hop) that is algorithmically detectable. Graph analysis reveals the structure.
"Exchange deposits are dead ends"
Most regulated exchanges require KYC. A deposit address + timestamp is sufficient for subpoena or law enforcement request.
"UTXO chains can't be clustered"
CoJoin heuristic (multiple inputs = common owner) clusters 60-80% of addresses on Bitcoin. CoinJoin must be explicitly filtered.
"I need full node data to trace"
Public block explorer APIs (Etherscan, mempool.space) are sufficient for 90% of cases. RPC nodes are only needed for raw event log parsing.
"Only one chain matters, the rest are noise"
Attackers almost always bridge to another chain. Ignoring cross-chain means missing the destination of funds.
"The trace is done when I hit a DeFi protocol"
DEX swaps and DeFi deposits leave logs too. Follow the LP tokens, check withdraw events, track the swap output tokens.
