WORM_MAINBOT.MCG

December 11, 2012
 ALIASES:

TrojanDropper:Win32/Dooxud.A (Microsoft); Generic Dropper.jb (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.Agent.aemu (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Worm.Generic.85189 (FSecure)

 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

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

  TECHNICAL DETAILS

File Size:

93,266 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Dec 2012

Arrival Details

This worm 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:

  • %System%\kav64.exe
  • %System%\kazaabackupfiles\shServ.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It creates the following folders:

  • %System%\kazaabackupfiles

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Microsoft Update = "kav64.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Update = "kav64.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Microsoft Update = "KAV64.EXE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Update = "KAV64.EXE"

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce

HKEY_CURRENT_USER\SOFTWARE\KAZAA\
LocalContent

It adds the following registry entries:

HKEY_CURRENT_USER\Software\KAZAA\
LocalContent
Dir0 = "012345:%System%\kazaabackupfiles"

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

Restart in Safe Mode

[ Learn More ]

Step 3

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_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
    • RunOnce
  • In HKEY_CURRENT_USER\SOFTWARE\KAZAA
    • LocalContent

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • Microsoft Update = "kav64.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Microsoft Update = "kav64.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • Microsoft Update = "KAV64.EXE"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Microsoft Update = "KAV64.EXE"
  • In HKEY_CURRENT_USER\Software\KAZAA\LocalContent
    • Dir0 = "012345:%System%\kazaabackupfiles"

Step 5

Search and delete this folder

[ 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.
  • %System%\kazaabackupfiles

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_MAINBOT.MCG. 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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