Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This file infector arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 181,760 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Mar 2015

Arrival Details

This file infector arrives via removable drives.

It 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 file infector drops the following files:

  • %Application Data%\{random folder name}\{random filename}.exe
  • %System%\{random filename}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It creates the following folders:

  • %Application Data%\{random folder name}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

Autostart Technique

This file infector 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\{Random}
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{Random}
DisplayName = "Windows Protection"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{Random}
ImagePath = "%System%\{random filename}.exe -k"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random Value} = "%Application Data%\{Random Folder}\{Random Filename}.exe"

Propagation

This file infector drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.

Other Details

This file infector connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.178.40/pki/mscorp/crl/msitwww2.crl
  • http://{BLOCKED}.{BLOCKED}.178.40/pki/mscorp/crl/MSIT%20Machine%20Auth%20CA%202(1).crl

It deletes the initially executed copy of itself

NOTES:

This malware infects files in removable and network drives with the following extensions:

  • .pdf
  • .msi
  • .doc
  • .ppt
  • .xls
  • .pptx
  • .docx
  • .xlsx
  • .pptx
  • .exe