ALIASES:

Dofoil, Smoaler, Downloader, Amokold, Injecter, Bredo

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

YAKES variants arrive on a system as a file dropped by other malware or downloaded unknowingly by users when visiting malicious sites. They may also arrive as attachments to spammed messages.

YAKES variants connect to websites to send and receive information. They usually connect to sites to inform remote malicious users about the installation. They may also connect to sites to download and execute malicious files.

Some variants may perform additional routines such as deleting files and disabling programs and applications from running properly. YAKES variants discontinue with routines if they detect certain security-related processes are running on affected systems.

  TECHNICAL DETAILS

Memory Resident: Yes
Payload: Connects to URLs/IPs

Installation

This Trojan drops the following copies of itself into the affected system:

  • %User Profile%\Application Data\csrss.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{random} = "%User Profile%\Application Data\csrss.exe"

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}etr.ru
  • {BLOCKED}dnic.ru
  • {BLOCKED}oko.ru
  • {BLOCKED}290.ru
  • {BLOCKED}ilzek.ru
  • {BLOCKED}nezo.ru