TROJ_KRYPTK.SM0

June 18, 2013
 ALIASES:

Rogue:Win32/FakeRean (Microsoft); Packed.Generic.328 (Symantec); Packed.Win32.Krap.il (Kaspersky); Worm.Win32.Rorpian (v) (Sunbelt); Trojan horse FakeAlert.ABS (AVG)

 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:

3,089,408 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 Jun 2013

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 drops the following copies of itself into the affected system:

  • %User Profile%\AntiVirus AntiSpyware 2011\securityhelper.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It creates the following folders:

  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011
  • %User Profile%\Application Data\AntiVirus AntiSpyware 2011

(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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
AntiVirus AntiSpyware 2011 Security = "{random characters}"

Other System Modifications

This Trojan deletes the following files:

  • {malware path and file name}:zone.identifier
  • %User Profile%\AntiVirus AntiSpyware 2011\securityhelper.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\_1.tmpac7d.exe
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011.lnk
  • %Desktop%\AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\Activate AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\How to Activate AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\Help AntiVirus AntiSpyware 2011.lnk
  • %User Profile%\Quick Launch\AntiVirus AntiSpyware 2011.lnk
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoActivate.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoHelp.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoMain.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoUninstall.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\AntiVirus AntiSpyware.exe
  • %User Profile%\AntiVirus AntiSpyware 2011\securitymanager.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

Restart in Safe Mode

[ Learn More ]

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\Microsoft\Windows\CurrentVersion\Run
    • AntiVirus AntiSpyware 2011 Security = "{random characters}"

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\_1.tmpac7d.exe
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011.lnk
  • %Desktop%\AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\Activate AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\How to Activate AntiVirus AntiSpyware 2011.lnk
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011\Help AntiVirus AntiSpyware 2011.lnk
  • %User Profile%\Quick Launch\AntiVirus AntiSpyware 2011.lnk
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoActivate.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoHelp.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoMain.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\IcoUninstall.ico
  • %User Profile%\AntiVirus AntiSpyware 2011\AntiVirus AntiSpyware.exe
  • %User Profile%\AntiVirus AntiSpyware 2011\securitymanager.exe

Step 5

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.
  • %Start Menu%\Programs\AntiVirus AntiSpyware 2011
  • %User Profile%\Application Data\AntiVirus AntiSpyware 2011

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_KRYPTK.SM0. 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.

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • {malware path and file name}:zone.identifier
  • %User Profile%\AntiVirus AntiSpyware 2011\securityhelper.exe


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