Analysis by: Anthony Joe Melgarejo

 ALIASES:

Trojan:Win32/Alureon.GC (Microsoft), Downloader.Liftoh (Symantec), W32/Slenfbot (McAfee), Trojan.Win32.Zbocheman.fb (v) (VIPRE), TR/Alureon.GC.10 (Antivir), W32/Trojan3.CAY (exact) (F-Prot), Trojan.Alureon (Ikarus), Win32/Gapz.E trojan (ESET)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

  TECHNICAL DETAILS

File Size: 79,872 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 04 Apr 2013
Payload: Connects to URLs/IPs, Compromises system security

Arrival Details

This backdoor 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 drops the following copies of itself into the affected system and executes them:

  • %All Users Profile%\Application Data\{random letters}sacfsfdsf.exe

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random letters}sacfsfdsf = "%All Users Profile%\Application Data\{random letters}sacfsfdsf.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\{random letters}sacfsfdsf

It adds the following registry entries:

HKEY_CURRENT_USER\Software\{random letters}sacfsfdsf
CurrentPath111 = "%All Users Profile%\Application Data\{random letters}sacfsfdsf.exe"

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}t.ru/power/c1.php
  • http://{BLOCKED}mcam.ru/power/c1.php