arrow_back
search
close

TROJ_AGENT_011028.TOMB

October 10, 2012
 ALIASES:

Trojan:Win32/Sisron (Microsoft); Generic VB.kf (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Swisyn.cfhj (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Gen:Variant.Barys.2229 (FSecure)

 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


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

It disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size:

217,088 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

09 Sep 2012

Arrival Details

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

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\Run
MSWUpdate = "%User Profile%\Microsoft\lsass.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MSWUpdate = "%User Profile%\Microsoft\lsass.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%User Profile%\Microsoft\lsass.exe"

(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
Microsoft\4842

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
MSWUpdate = "%User Profile%\Microsoft\lsass.exe"

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
Microsoft\4842
F = "True"

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
MSWUpdate = "%User Profile%\Microsoft\lsass.exe"

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Identify and delete files detected as TROJ_AGENT_011028.TOMB using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware.

Step 4

Delete this registry key

[ 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
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • Run
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\Microsoft
    • 4842

Step 5

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • MSWUpdate = "%User Profile%\Microsoft\lsass.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • MSWUpdate = "%User Profile%\Microsoft\lsass.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • MSWUpdate = "%User Profile%\Microsoft\lsass.exe"
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\Microsoft\4842
    • F = "True"

Step 6

Restore this modified 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 NT\CurrentVersion\Winlogon
    • From: Userinit = "%System%\userinit.exe,%User Profile%\Microsoft\lsass.exe"
      To: Userinit = ""%Windows%\system32\userinit.exe,""

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT_011028.TOMB. 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.


Did this description help? Tell us how we did.