Skip to content

Export page to PDF
TROJ_BAMITAL.SMK
Aliases: Trojan:Win32/Ransom.CF (Microsoft); W32/Bamital.h (McAfee); Trojan-Ransom.Win32.PornoBlocker.del (Kaspersky); Trojan.Win32.Bamital.i (v) (Sunbelt); Gen:Variant.Kazy.4786 (FSecure)
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
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: 103,936 bytes
File type: EXE
Memory resident: Yes
Initial samples received date: 05 Nov 2011

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "{malware path and file name}.exe"

(Note: The default value data of the said registry entry is Explorer.exe.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Outlook Express
palo = "1117568389"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Outlook Express
mynum = "89853366153"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\SafeBoot
AlternateShell = "{malware path and file name}.exe"

(Note: The default value data of the said registry entry is cmd.exe.)

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = 1

This report is generated via an automated analysis system.

Solution


Minimum scan engine: 9.200

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and delete files detected as TROJ_BAMITAL.SMK 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/spyware.

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\Outlook Express
    • palo="1117568389"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Outlook Express
    • mynum="89853366153"

Step 5

Restore these modified registry values

[ Learn more ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.


  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SafeBoot
    • From: AlternateShell="{malware path and file name}.exe"
      To: AlternateShell=cmd.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Shell="{malware path and file name}.exe"
      To: Shell=Explorer.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_BAMITAL.SMK. 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.
Analysis By: Automation

Social Media Links

Connect with us on