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TSPY_DYRE.AAUA

January 13, 2015
 Analysis by: Homer Pacag
 ALIASES:

PWS:Win32/Dyzap.F (Microsoft); Infostealer.Dyranges (Symantec);

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

392,192 bytes

File Type:

EXE

Initial Samples Received Date:

17 Dec 2014

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 drops the following copies of itself into the affected system:

  • %AppDataLocal%\{random filename}.exe (for Windows Vista and above)
  • %Windows%\{random filename}.exe (for Windows XP and below)

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Autostart Technique

This spyware registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\googleupdate
ImagePath = "%Windows%\{random filename}.exe" (for Windows XP and below)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\googleupdate
DisplayName = "Google Update Service" (for Windows XP and below)

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
(Default) = "%AppDataLocal%\{random filename}.exe" (for Windows Vista and above)

Dropping Routine

This spyware drops the following files:

  • %System%\config\systemprofile\Application Data\{random filename}.vas (for Windows Vista and above)
  • %AppDataLocal%\{random filename}.vas (for Windows XP and below)

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This spyware connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.250.138:443
  • {BLOCKED}.{BLOCKED}.198.196:4443
  • {BLOCKED}.{BLOCKED}.134.53:4443
  • {BLOCKED}.{BLOCKED}.35.133:4443 !
  • {BLOCKED}.{BLOCKED}.214.154:443
  • {BLOCKED}.{BLOCKED}.184.74:4443
  • {BLOCKED}.{BLOCKED}.181.164:4443
  • {BLOCKED}.{BLOCKED}.17.152:4443
  • {BLOCKED}.{BLOCKED}.17.155:4443
  • {BLOCKED}.{BLOCKED}.17.158:4443

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.356.04

FIRST VSAPI PATTERN DATE:

17 Dec 2014

VSAPI OPR PATTERN File:

11.357.00

VSAPI OPR PATTERN Date:

17 Dec 2014

Scan your computer with your Trend Micro product to delete files detected as TSPY_DYRE.AAUA. 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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