Proxy: External Proxy

APT28 used other victims as proxies to relay command traffic, for instance using a compromised Georgian military email server as a hop point to NATO victims. The group has also used a tool that acts as a proxy to allow C2 even if the victim is behind a router. APT28 has also used a machine to relay and obscure communications between CHOPSTICK and their server.^[2][3][4]

APT29 uses compromised residential endpoints as proxies for defense evasion and network access.^[5]

An APT3 downloader establishes SOCKS5 connections for its initial C2.^[6]

APT39 has used various tools to proxy C2 communications.^[7]

FIN5 maintains access to victim environments by using FLIPSIDE to create a proxy for a backup RDP tunnel.^[8]

GALLIUM used a modified version of HTRAN to redirect connections between networks.^[9]

InvisiMole InvisiMole can identify proxy servers used by the victim and use them for C2 communication.^[10][11]

Lazarus Group has used multiple proxies to obfuscate network traffic from victims.^[12][13]

menuPass has used a global service provider's IP as a proxy for C2 traffic from a victim.^[14][15]

MuddyWater has controlled POWERSTATS from behind a proxy network to obfuscate the C2 location.^[16] MuddyWater has used a series of compromised websites that victims connected to randomly to relay information to command and control (C2).^[17][18]

Mythic can leverage a modified SOCKS5 proxy to tunnel egress C2 traffic.^[19]

Okrum can identify proxy servers configured and used by the victim, and use it to make HTTP requests to C2 its server.^[20]

POWERSTATS has connected to C2 servers through proxies.^[21]

QakBot has a module that can proxy C2 communications.^[22]

Quad7 Activity has initialized SOCKS5 proxies on compromised devices.^[23][24]

QUIETEXIT can proxy traffic via SOCKS.^[25]

Regin leveraged several compromised universities as proxies to obscure its origin.^[26]

ShimRat can use pre-configured HTTP proxies.^[27]

Silence has used ProxyBot, which allows the attacker to redirect traffic from the current node to the backconnect server via Sock4\Socks5.^[28]

Tonto Team has routed their traffic through an external server in order to obfuscate their location.^[29]

TrickBot has been known to reach a command and control server via one of nine proxy IP addresses. ^{[30] [31]}

The Winnti for Windows HTTP/S C2 mode can make use of an external proxy.^[32]

Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level. Signatures are often for unique indicators within protocols and may be based on the specific C2 protocol used by a particular adversary or tool, and will likely be different across various malware families and versions. Adversaries will likely change tool C2 signatures over time or construct protocols in such a way as to avoid detection by common defensive tools.^[33]