BKDR_HOSTIL.D

 Analysis by: Christopher Daniel So

 ALIASES:

Backdoor.Cycbot (Symantec)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This backdoor arrives as attachment to mass-mailed email messages. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes then deletes itself afterward.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

15,360 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

24 Mar 2011

Payload:

Downloads files

Arrival Details

This backdoor arrives as attachment to mass-mailed email messages.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor executes then deletes itself afterward.

Download Routine

This backdoor accesses the following websites to download files:

  • http://{BLOCKED}.{BLOCKED}.121.33/lol2.exe
  • http://{BLOCKED}.{BLOCKED}.121.33/pod.exe
  • http://{BLOCKED}.{BLOCKED}.121.33/spm.exe
  • http://{BLOCKED}.{BLOCKED}.35.159/lol2.exe
  • http://{BLOCKED}.{BLOCKED}.35.159/pod.exe
  • http://{BLOCKED}.{BLOCKED}.35.159/spm.exe

It saves the files it downloads using the following names:

  • %User Temp%\lol2.exe
  • %User Temp%\pod.exe
  • %User Temp%\spm.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

As of this writing, the said sites are inaccessible.