Analysis by: Anthony Joe Melgarejo

ALIASES:

VirTool:Win32/VBInject.gen!BF (Microsoft), W32.IRCBot (Symantec), W32/Hamweq.worm.aq (McAfee)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

It monitors certain processes to steal user credentials.

This worm arrives via removable drives. It may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

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: 180265 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 16 Sep 2011

Arrival Details

This worm arrives via removable drives.

It may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %System%\traymgr.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
MicrosoftCorp = %System%\traymgr.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MicrosoftNAPC = %System%\traymgr.exe

Propagation

This worm creates the following folders in all removable drives:

  • {drive letter}:\ice
  • {drive letter}:\ice\fire

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

  • {drive letter}:\ice\fire\traymgr.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]
[autorun[
[autorun]
open=ice\fire\traymgr.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
UseAuTOPLAY=1
shell\open\command=ice\fire\traymgr.exe
shell\Explore\Command=ice\fire\traymgr.exe

Other Details

This worm connects to the following possibly malicious URL:

  • {BLOCKED}r.{BLOCKED}014.com

  SOLUTION

Minimum Scan Engine: 9.300
VSAPI OPR PATTERN File: 9.477.00
VSAPI OPR PATTERN Date: 21 Oct 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Terminate a malware/grayware process

[ Learn More ]

*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.

    • traymgr.exe

Step 3

Identify and delete files detected as WORM_KOLAB.ZFX using either the Startup Disk or Recovery Console

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • MicrosoftCorp = "%System%\traymgr.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • MicrosoftNAPC = "%System%\traymgr.exe"

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {drive letter}:\ice

Step 6

Search and delete AUTORUN.INF files created by WORM_KOLAB.ZFX that contain these strings

[ Learn More ]
autorun]
[autorun[
[autorun]
open=ice\fire\traymgr.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
UseAuTOPLAY=1
shell\open\command=ice\fire\traymgr.exe
shell\Explore\Command=ice\fire\traymgr.exe

Step 7

Scan your computer with your Trend Micro product to delete files detected as WORM_KOLAB.ZFX. 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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