PE_QUERVAR.B

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

It prepends its codes to target files. It adds infection markers to files.

It creates an event. However, as of this writing, the said sites are inaccessible.

Arrival Details

This file infector 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 component file(s):

• %Application Data%\{random folder name}\{random file name}.exe.ini
• %Application Data%\{random folder name}\{random file name}.exe.lnk

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It drops and executes the following files:

• %Application Data%\{random folder name}\{random file name}.exe - detected as PE_QUERVAR.B-O

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%Application Data%\{random folder name}\{random file name}.exe.lnk"

File Infection

This file infector infects the following file types:

• EXE
• DOC
• DOCX
• XLS
• XLSX

It prepends its codes to target files.

It adds infection markers to files.

Process Termination

This file infector terminates the following processes if found running in the affected system's memory:

• taskmgr.exe

Other Details

Based on analysis of the codes, it has the following capabilities:

• Attempts to connect to the following remote registry using Remote Registry Service: HKEY_CURRENT_USER\kaspersky
• Update the malware copy.
• Change the file names and folder name randomly.
• Change the hash randomly on command.

It attempts to access the following websites to download files, which are possibly malicious:

• http://www.update.{BLOCKED}t.com/windowsupdate/v6/thanks.aspx?{random}&pin={random}
• http://{BLOCKED}dns.com/bl/in.php?{random}&pin={random}

It creates the following event(s):

• "SayHellotomyLittleFriend"

However, as of this writing, the said sites are inaccessible.

NOTES:

Infected files are renamed depending on the file extension of the original file:

• {original file name}.doc to {original file name}cod.scr
• {original file name}.docx to {original file name}xcod.scr
• {original file name}.xls to {original file name}slx.scr
• {original file name}.xlsx to {original file name}xslx.scr

It searches for target drives by looking for drives without the System Volume Information folder to prevent infection of files in local hard drives.