ALIASES:

Trojan:Win32/Dwinlo.A (Microsoft); [0007a064.EXE\0007a064.EXE]:Keylog-Bansaka.dll (McAfee); IRC Trojan (Symantec); Trojan-Spy.Win32.Delf.uo (Kaspersky); BehavesLike.Win32.Malware.eah (mx-v) (Sunbelt); Trojan horse PSW.Generic4.UTB (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware 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: 511,488 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 Oct 2013

Arrival Details

This spyware 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 spyware creates the following folders:

  • %Windows%\Driver Cache\Winapp
  • %Windows%\Driver Cache\Winapp\AppData

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

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
winloader = "%Windows%\Driver Cache\Winapp\AppData\lssass.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
winload = "%Windows%\Driver Cache\i386\msdbgview.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce

HKEY_LOCAL_MACHINE\Software\cupra\
checker

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\cupra\
checker
wstring = "1"

Dropping Routine

This spyware drops the following files:

  • %Windows%\Driver Cache\Winapp\AppData\mousehook.dll
  • %Windows%\Driver Cache\Winapp\AppData\lssass.exe
  • %Windows%\Driver Cache\i386\msdbgview.exe
  • %Windows%\Driver Cache\Winapp\AppData\ioerrors.txt

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

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 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\Windows\CurrentVersion
    • RunOnce
  • In HKEY_LOCAL_MACHINE\Software\cupra
    • checker

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\RunOnce
    • winloader = "%Windows%\Driver Cache\Winapp\AppData\lssass.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • winload = "%Windows%\Driver Cache\i386\msdbgview.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\cupra\checker
    • wstring = "1"

Step 5

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.
  • %Windows%\Driver Cache\Winapp\AppData\mousehook.dll
  • %Windows%\Driver Cache\Winapp\AppData\lssass.exe
  • %Windows%\Driver Cache\i386\msdbgview.exe
  • %Windows%\Driver Cache\Winapp\AppData\ioerrors.txt

Step 6

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.
  • %Windows%\Driver Cache\Winapp
  • %Windows%\Driver Cache\Winapp\AppData

Step 7

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