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TROJ_BUZUS.ZYX

October 09, 2012
 Modified by: Jed Valderama
 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

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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 connects to a website to send and receive information.

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

320,512 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

No

Initial Samples Received Date:

10 Apr 2010

Payload:

Connects to URLs/IPs, Drops files

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 adds the following folders:

  • %Application Data%\SystemProc
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}\chrome
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}\chrome\content

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

It drops the following files:

  • %User Temp%\{random filename}.htm - detected as TSPY_SASFIS.AE
  • %User Temp%\plsec.exe - detected as TROJ_BREDO.SMX
  • %User Temp%\setup.exe - detected as TROJ_SASFIS.AE
  • %Program Files%\Internet Explorer\rasadhlp.dll - detected as TSPY_SASFIS.AE
  • %Program Files%\Mozilla Firefox\rasadhlp.dll - detected as TSPY_SASFIS.AE
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}\chrome\content\timer.xul - detected as TROJ_DURSG.ZYX

(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.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

It drops the following non-malicious files:

  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}\chrome.manifest
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}\install.rdf

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

It drops the following copies of itself into the affected system:

  • %Application Data%\SystemProc\lsass.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

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\policies\
Explorer\Run
RTHDBPL = "%Application Data%\SystemProc\lsass.exe"

Backdoor Routine

This Trojan connects to the following websites to send and receive information:

  • http://{BLOCKED}trol.com/inst.php?aid=blackout

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

7.250.07

FIRST VSAPI PATTERN DATE:

10 Apr 2010

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

Remove malware/grayware files dropped/downloaded by TROJ_BUZUS.ZYX

    • TSPY_SASFIS.AE
    • TROJ_BREDO.SMX
    • TROJ_SASFIS.AE
    • TROJ_DURSG.ZYX

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_BUZUS.ZYX

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • RTHDBPL = "%Application Data%\SystemProc\lsass.exe"

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.
  • %Application Data%\SystemProc
  • %Program Files%\Mozilla Firefox\extensions\{8CE11043-9A15-4207-A565-0C94C42D590D}

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_BUZUS.ZYX. 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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