Analysis by: Christopher Daniel So
ALIASES:

Backdoor:Linux/Shellshock.A (Microsoft)

 PLATFORM:

Linux, UNIX

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This malware is involved in the Bash Vulnerability Exploit attack of September 2014. It is capable of compromising an affected system's security by carrying out commands made by a malicious remote user. In the attack, it is utilized to perform distributed denial-of-service (DDoS) attacks as well as brute-forcing logins in order to steal login credentials.

This backdoor executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 51,804 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 03 Oct 2014
Payload: Compromises system security, Connects to URLs/IPs, Collects system information

Arrival Details

This malware arrives via the following means:

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • UDP - Perform UDP flooding
  • TCP - Perform TCP flooding
  • LOLNOGTFO - terminate botnet
  • KILLATTK - terminate attack thread
  • JUNK - Perform Junk Flooding
  • HOLD - Pause or delay attack for specified duration
  • GETLOCALIP - Get Local IP address
  • PING
  • SCANNER

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}9.{BLOCKED}8.150.154:5

NOTES:

It uses the following list of user names and passwords to brute force login:

  • root
  • user
  • login
  • guest
  • toor
  • admin
  • user
  • guest
  • login
  • changeme
  • 1234
  • 12345
  • 123456
  • default
  • pass
  • password

It gathers the following information:

  • CPU information (/proc/cpuinfo)
  • Network information (/proc/net/route)

If the SCANNER command is ON, it executes the following to check if system is a honeypot:

/bin/busybox;echo -e ‘gayfgt’\r\n

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.188.05
FIRST VSAPI PATTERN DATE: 03 Oct 2014
VSAPI OPR PATTERN File: 11.189.00
VSAPI OPR PATTERN Date: 04 Oct 2014

Restart in normal mode and scan your computer with your Trend Micro product for files detected as ELF_BASHLITE.E. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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