T1090.003: Proxy: Multi-hop Proxy (Use of Tor/I2P for C2)

Framework: MITRE ATT&CK · Tactic: Command and Control · Total Cataloged Families: 13 · Observed Samples: 12,691 · Primary Threat Categories: Ransomware · Trojan · Advanced Threat

Operational Executive Summary

T1090.003 (Proxy: Multi-hop Proxy (Use of Tor/I2P for C2)) is classified under the Command and Control tactic within the MITRE ATT&CK framework. Communication channels and covert protocols utilized to maintain interactive control of compromised implants through legitimate web protocols, encrypted proxies, and DNS tunneling. In telemetry gathered across enterprise endpoints and the EMBER 2018 benchmark, this technique was weaponized across 13 distinct malware families, totaling over 12,691 validated samples.

Technical Anatomy & Adversary Tradecraft

Adversaries leverage Proxy: Multi-hop Proxy (Use of Tor/I2P for C2) to accomplish operational objectives while minimizing anomalous forensic footprints. When executing Proxy: Multi-hop Proxy (Use of Tor/I2P for C2), malicious binaries commonly interact directly with low-level Windows APIs, kernel mode drivers, or native scripting interfaces to bypass traditional file-integrity monitors and static antivirus signatures.

In modern multi-stage campaigns, T1090.003 is frequently observed functioning as an intermediate bridge: initial access payloads (such as spearphishing loaders or exploit macros) execute Proxy: Multi-hop Proxy (Use of Tor/I2P for C2) to establish in-memory execution or persistence before staging secondary ransomware or data-exfiltration implants.

Authoritative MITRE ATT&CK Reference: View official technique documentation, sub-techniques, and adversary groups at https://attack.mitre.org/techniques/T1090/003/.

Detection Engineering & Threat Hunting

Detecting Proxy: Multi-hop Proxy (Use of Tor/I2P for C2) requires telemetry correlation across endpoint detection and response (EDR) agents, Sysmon event streams, and security information event management (SIEM) pipelines:

Process Creation & Lineage: Monitor parent-child process anomalies where unexpected parent binaries (e.g., Office executables, web browsers, or script hosts) spawn command shells or native Windows utilities.
API Hooking & Behavioral Telemetry: EDR platforms should flag rapid calls to memory allocation, process injection, or registry manipulation APIs originating from unbacked executable memory regions.
Network Anomaly Correlation: Cross-reference endpoint execution timestamps with external network socket establishment to identify anomalous beaconing or covert data staging.

SOC Containment & Hardening Guidance

To mitigate risks associated with T1090.003 (Proxy: Multi-hop Proxy (Use of Tor/I2P for C2)) across production infrastructure, security teams should implement the following defensive controls:

Attack Surface Reduction (ASR): Enforce strict application control policies (WDAC or AppLocker) to restrict execution to signed and verified corporate binaries.
Least Privilege & Credential Hygiene: Restrict local administrative privileges to prevent adversaries from tampering with defensive agents or escalating privileges.
Network Microsegmentation: Restrict lateral communication across endpoint VLANs to prevent wormable payloads from utilizing Proxy: Multi-hop Proxy (Use of Tor/I2P for C2) across adjacent network segments.

→ Incident Response Guidance: Read our Botnet Protection & Remediation

Cataloged Malware Families Utilizing T1090.003 (13 Families)

The following malware families in the SystemHelpDesk catalog have been verified utilizing T1090.003 (Proxy: Multi-hop Proxy (Use of Tor/I2P for C2)):

13 families

Family	Category	Sample Count	Technical Summary
vtflooder	Pua Tool	`12,150`	VtFlooder (tracked across enterprise threat intelligence as Trojan:Win32/VtFlooder, Tool:Win32/VtFlooder, and Spammer:Win32/VtFlooder) is an automated cloud sub...
koobface	Worm	`350`	Koobface (an anagram of 'Facebook') was the definitive pioneer of social-network worm and botnet operations, reigning as one of the most prolific and profitable...
shade	Ransomware	`72`	Shade (also widely tracked in cyber threat intelligence feeds as Troldesh, Encoder.858, and Ransom:Win32/Shade) is a landmark ransomware family that terrorized ...
stormattack	Trojan	`62`	StormAttack (cataloged across security vendors and threat intelligence databases under signatures including Trojan:Win32/StormAttack and Trojan:Win32/StormAttac...
troldesh	Ransomware	`14`	Troldesh (widely tracked across the intelligence community as Shade or Encrypter.JPHP) is a notorious Russian-speaking ransomware family first active in late 20...
retefe	Trojan	`13`	Retefe (historically documented as Trojan:Win32/Retefe and Trojan-Banker.Win32.Retefe) is a sophisticated banking trojan that actively targeted banking institut...
sefnit	Trojan	`11`	Trojan:Win32/Sefnit (often tracked as the Mevade botnet) was a massive, highly sophisticated botnet that infected millions of machines globally between 2013...
ultrasurf	Advanced Threat	`7`	PUA:Win32/Ultrasurf represents a unique classification in enterprise security. Technically, Ultrasurf is a freeware Internet censorship circumvention tool, orig...
proxyweb	Trojan	`4`	Trojan:Win32/Proxyweb is a type of malware that silently converts an infected endpoint into a proxy server or relay node for a larger botnet. Instead of stealin...
crowti	Ransomware	`3`	Ransom:Win32/Crowti is Microsoft's internal detection designation for the infamous CryptoWall ransomware family. Emerging in the mid-2010s as a successor to...
sage	Ransomware	`3`	Ransomware:Win32/Sage (specifically known as Sage 2.0) is a highly destructive crypto-ransomware family that gained significant notoriety in early 2017. A varia...
proxygate	Advanced Threat	`1`	<h3>Executive Summary</h3> ProxyGate is an application typically classified as Riskware or a Potentially Unwanted Program (PUP) by enterprise security environme...
zero	Ransomware	`1`	<h3>Executive Summary</h3> While "Zero" can occasionally refer to minor ransomware variants, in enterprise security contexts, it most commonly refers to the Zer...