XTunnel

XTunnel a VPN-like network proxy tool that can relay traffic between a C2 server and a victim. It was first seen in May 2013 and reportedly used by APT28 during the compromise of the Democratic National Committee. [1] [2] [3]

ID: S0117
Associated Software: Trojan.Shunnael, X-Tunnel, XAPS
Type: MALWARE
Platforms: Windows
Version: 2.1
Created: 31 May 2017
Last Modified: 21 March 2020

Associated Software Descriptions

Name Description
Trojan.Shunnael [4]
X-Tunnel [1][4]
XAPS [3]

Techniques Used

Domain ID Name Use
Enterprise T1059 .003 Command and Scripting Interpreter: Windows Command Shell

XTunnel has been used to execute remote commands.[1]

Enterprise T1573 .002 Encrypted Channel: Asymmetric Cryptography

XTunnel uses SSL/TLS and RC4 to encrypt traffic.[2][3]

Enterprise T1008 Fallback Channels

The C2 server used by XTunnel provides a port number to the victim to use as a fallback in case the connection closes on the currently used port.[3]

Enterprise T1046 Network Service Scanning

XTunnel is capable of probing the network for open ports.[2]

Enterprise T1027 Obfuscated Files or Information

A version of XTunnel introduced in July 2015 obfuscated the binary using opaque predicates and other techniques in a likely attempt to obfuscate it and bypass security products.[3]

.001 Binary Padding

A version of XTunnel introduced in July 2015 inserted junk code into the binary in a likely attempt to obfuscate it and bypass security products.[3]

Enterprise T1090 Proxy

XTunnel relays traffic between a C2 server and a victim.[1]

Enterprise T1552 .001 Unsecured Credentials: Credentials In Files

XTunnel is capable of accessing locally stored passwords on victims.[2]

Groups That Use This Software

ID Name References
G0007 APT28

[5][4]

References