recovering-from-ransomware-attack

name	recovering-from-ransomware-attack
description	Use when executing structured recovery from a ransomware incident following NIST and CISA frameworks, including environment isolation, forensic evidence preservation, clean infrastructure rebuild, prioritized system restoration from verified backups, credential reset, and validation against re-infection. Covers Active Directory recovery, database restoration, and application stack rebuild in dependency order.
domain	cybersecurity
tags	["ransomware","recovery","incident-response","backup","defense"]
subdomain	ransomware-defense
version	1.0.0
author	oyi77
license	Apache-2.0
nist_csf	["PR.DS-11","RS.MA-01","RC.RP-01","PR.IR-01"]

Recovering From Ransomware Attack

Overview

Cybersecurity skill for recovering from ransomware attack. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "recovering from ransomware attack"

• "Executes structured recovery from a ransomware incident following NIST and CISA "

• After ransomware has encrypted production systems and the decision has been made to recover from backups

• When building or validating a ransomware recovery runbook before an actual incident

• After receiving a decryption key (paid ransom or law enforcement provided) and needing to safely decrypt

• When partial recovery is needed alongside decryption of remaining systems

• Conducting a recovery drill to validate RTO commitments

Do not use before completing containment and forensic scoping. Premature recovery without understanding the attacker's access and persistence mechanisms risks re-infection.

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• Incident declared and containment phase completed (all attacker access severed)
• Forensic evidence preserved (disk images, memory dumps, network captures)
• Backup integrity verified (immutable/air-gapped copies confirmed clean)
• Clean build media available (OS installation media, golden images)
• Recovery environment prepared (clean network segment isolated from compromised infrastructure)
• Recovery priority list documented (Tier 1/2/3 systems in dependency order)

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs() -> :
     {k: re.findall(v, text)  k, v  IOC_PATTERNS.items()}