ALIASES:

MonitoringTool:Win32/Actmon, MonitoringTool:Win32/Actmon, MonitoringTool:Win32/Actmon, MonitoringToo (Microsoft); [IMAPD.EXE]:Generic Malware.eb, [IMAPDB.DLL\IMAPDB.DLL]:Spyware-ActMon., [IMAPDB.EXE]:Generic PUP.x. (McAfee); Trojan.Dropper (Symantec); ARC:RAR, PAK:[imapd.exe]:NPack, PAK:[imapdb.dll]:NPack, PAK:[imapdb.exe]:NPack, PAK:[imapdc.dll]:NPa (Kaspersky); Trojan.Win32.Packer.nPack1.1.30 (ep), Trojan.Win32.Packer.nPack1.1.30 (ep), Trojan.Win32.Packer.nPac (Sunbelt); Dropped:Application.Generic.13515 (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.

  TECHNICAL DETAILS

File Size: 713,664 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Jan 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.

Installation

This Trojan creates the following folders:

  • %System Root%\Documents and Settings
  • %System Root%\Documents and Settings\Administrator
  • %User Profile%\Application Data
  • %User Profile%\Application Data\dxdlls

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\WinRAR SFX

It adds the following registry entries:

HKEY_CURRENT_USER\Software\WinRAR SFX
C%%Documents and Settings%Administrator%Application Data%dxdlls = {random characters}

Dropping Routine

This Trojan drops the following files:

  • imapd.exe
  • imapdb.dll
  • imapdb.exe
  • imapdc.dll
  • wproxp.exe
  • ActMon.ini

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

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
    • WinRAR SFX

Step 3

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\WinRAR SFX
    • C%%Documents and Settings%Administrator%Application Data%dxdlls={random characters}

Step 4

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.
  • %System Root%\Documents and Settings
  • %System Root%\Documents and Settings\Administrator
  • %User Profile%\Application Data
  • %User Profile%\Application Data\dxdlls

Step 5

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • imapd.exe
  • imapdb.dll
  • imapdb.exe
  • imapdc.dll
  • wproxp.exe
  • ActMon.ini

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_SMALL.NAV. 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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