Analysis by: Jaime Benigno Reyes
ALIASES:

Trojan:Win32/Rimecud.A (Microsoft), P2P-Worm.Win32.Palevo.gkji (Kaspersky), W32/Worm-FDQ!A14E793B0B2B (McAfee), Trojan.ADH.2 (Symantec)

 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: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm arrives by connecting affected removable drives to a system. 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 drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 79,517 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 08 Mar 2013

Arrival Details

This worm arrives by connecting affected removable drives to a system.

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 worm drops the following copies of itself into the affected system:

  • %User Profile%\etkrkf.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%User Profile%\etkrkf.exe"

Propagation

This worm creates the following folders in all removable drives:

  • {removable drive letter}:\hurgheda

It drops the following copy(ies) of itself in all removable drives:

  • {removable drive letter}:\hurgheda\exwan.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
{gabage}
shell\\open\\command=hurgheda\exwan.exe
{gabage}
action=Open folder to view files using Windows Explorer
{gabage}
Shell\\Open\\command=hurgheda\exwan.exe
{gabage}
shellexecute=hurgheda\exwan.exe
{gabage}
shell\\explore\\command=hurgheda\exwan.exe
{gabage}
icon=SHELL32.dll,4
{gabage}
open=hurgheda\exwan.exe
{gabage}
USEAUTOPLAY=1
{gabage}

Other Details

This worm connects to the following possibly malicious URL:

  • {BLOCKED}a.{BLOCKED}e.com
  • {BLOCKED}a.{BLOCKED}k.net
  • {BLOCKED}a.{BLOCKED}est.com
  • {BLOCKED}t.{BLOCKED}e.kz