Analysis by: Mark Joseph Manahan
ALIASES:

Trojan.Win32.Spy (Ikarus)

 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 as a component bundled with malware/grayware packages.

  TECHNICAL DETAILS

File Size: 53,248 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 31 Aug 2012

Arrival Details

This Trojan arrives as a component bundled with malware/grayware packages.

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias
ImagePath = "%SystemRoot%\System32\svchost.exe -k netsvcs"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias
Description = "Internet Authentication Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias
DisplayName = "Ias Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias\Parameters
ServiceDll = "{malware path and filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias
Start = "2"

It adds and runs the following services:

  • Ias Service

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_IAS

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ias\Parameters

NOTES:

This Trojan requires the following file to run its intended routine:

  • %System%\tnsy39.tmp

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.370.01
FIRST VSAPI PATTERN DATE: 04 Sep 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

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root
    • LEGACY_IAS
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • Ias

Step 4

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