Rewterz Threat Alert – B1txor20 – Active IOCs

Severity

Medium

Analysis Summary

B1txor20 is a linxu-based backdoor which builds C2 communication channels using DNS Tunnel Technology. Along with its traditional backdoors, it also has functions like Socket5 proxy and remote installation and downloading rootkits. Since it is a fairly new backdoor, there are still some bugs present in the backdoor. The backdoor uses ZLIB compression, Base64 encoding, and RC4 encryption to protect it’s traffic. The main features currently supported are shown below.

1. SHELL
2. Proxy
3. Execute arbitrary commands
4. Install Rootkit
5. Upload sensitive information

Basic Flowchart from Netlab.

Impact

• Information Theft and Espionage
• Exposure of Sensitive Data

Indicators of Compromise

IP

• 194[.]165[.]16[.]24

URL

• http[:]//179[.]60[.]150[.]23[:]8000/xExportObject[.]class
• http[:]//194[.]165[.]16[.]24[:]8229/b1t_1t[.]sh
• http[:]//194[.]165[.]16[.]24[:]8228/b1t
• http[:]//194[.]165[.]16[.]24[:]8228/_run[.]sh
• http[:]//194[.]165[.]16[.]24[:]8229/b4d4b1t[.]elf

Remediation

• Block all threat indicators at your respective controls.
• Search for IOCs in your environment.