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TROJ_KRYPTIK.AW

April 11, 2014
 Modified by: Adrian Cofreros
 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:

143,360 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Apr 2014

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:

  • %Windows%\eRegr.exe
  • %Windows%:eRegr.exe (ADS)
  • %Application Data%:eRegr.exe (ADS)
  • %Windows%\AdobeDis.exe
  • %Application Data%\AdobeDis.exe

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Technologies = "%Windows%:eRegr.exe"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Technologies = "%Application Data%:eRegr.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Technologies = "%Windows%\eRegr.exe"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
AdoberDis = "%Application Data%\AdobeDis.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
AdoberDis = "%Windows%\AdobeDis.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\MCD

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
Enable = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
SwapSync = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
Palettized Formats = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
IO Priority = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
Use Generic Stencil = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\MCD
Enumerate as ICD = "0"

Other Details

This Trojan connects to the following possibly malicious URL:

  • https://{BLOCKED}de.{BLOCKED}ess.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.706.03

FIRST VSAPI PATTERN DATE:

04 Apr 2014

VSAPI OPR PATTERN File:

10.707.00

VSAPI OPR PATTERN Date:

05 Apr 2014

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 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\Software\Microsoft\Windows\CurrentVersion
    • MCD

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\Run
    • Technologies = "%Application Data%:eRegr.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Technologies = "%Windows%\eRegr.exe"
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • AdoberDis = "%Application Data%\AdobeDis.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • AdoberDis = "%Windows%\AdobeDis.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Technologies = "%Windows%:eRegr.exe"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_KRYPTIK.AW. 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 6

To delete ADS files:

  1. Download Streams.exe from this Microsoft page.
  2. Extract the contents of this file to a location of your choice.
  3. Open a command prompt window. To do this:
    • On Windows 2000, XP, and Server 2003:
      Click Start>Run. In the input box, type CMD, and press Enter.
    • On Windows Vista and 7:
      Click the Windows button, type CMD in the search box, and press Enter.
  4. In the command prompt, type the following, then press Enter:
    CD {Path where contents of downloaded file was extracted}
  5. Still in the command prompt type the following then press Enter:
    Streams.exe -d
    • %Windows%:eRegr.exe
    • %Application Data%:eRegr.exe
  6. Type exit then press Enter.


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