ALIASES:

Trojan:Win32/EyeStye.AE (Microsoft); PWS-Spyeye.e (McAfee); Trojan.Gen.2 (Symantec); Trojan-Spy.Win32.SpyEyes.dzs (Kaspersky); VirTool.Win32.Obfuscator.da!j (v) (Sunbelt); Found Win32/DH{Ex4UTxUb} (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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 272,384 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 03 Oct 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:

  • %System Root%\portwexexe.exe\portwexexe.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

  • %System Root%\portwexexe.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log

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

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\DBControl

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Cache\Paths\path1
CacheLimit = "13fa6"

(Note: The default value data of the said registry entry is ffac.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Cache\Paths\path2
CacheLimit = "13fa6"

(Note: The default value data of the said registry entry is ffac.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Cache\Paths\path3
CacheLimit = "13fa6"

(Note: The default value data of the said registry entry is ffac.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
Cache\Paths\path4
CacheLimit = "13fa6"

(Note: The default value data of the said registry entry is ffac.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\portwexexe.exe\config.bin

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This Trojan deletes itself after execution.

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

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\Internet Explorer
    • DBControl

Step 3

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1
    • From: CacheLimit = "13fa6"
      To: CacheLimit = ""ffac""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2
    • From: CacheLimit = "13fa6"
      To: CacheLimit = ""ffac""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3
    • From: CacheLimit = "13fa6"
      To: CacheLimit = ""ffac""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4
    • From: CacheLimit = "13fa6"
      To: CacheLimit = ""ffac""

Step 4

Search and delete this file

[ Learn More ]
There may be some 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.
  • %System Root%\portwexexe.exe\config.bin

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 Root%\portwexexe.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_SPYEYES.T. 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.

  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log


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