PE_EXPIRO.ZZ

This file infector may arrive as an infected file.

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 infects files by overwriting code in the entry point and saving the overwritten code in the virus body. It then appends the virus body to the host file. It creates an infection marker in infected files.

It connects to a website to send and receive information.

It modifies the Internet Explorer Zone Settings.

It steals certain information from the system and/or the user.

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 file(s)/component(s):

• %Application Data%\{Volume serial of system folder}{number}.nls - non-malicious

(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 adds the following mutexes to ensure that only one of its copies runs at any one time:

• kkq-vx-mtx{number}

Other System Modifications

This file infector adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\0
2103 = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
2103 = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
2103 = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2103 = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
2103 = "0"

File Infection

This file infector infects the following file types:

• .EXE

It overwrites code found in the entry point of a target file. It then appends the virus body to the target file. The overwritten code is saved in the virus body.

It creates an infection marker in infected files.

Propagation

This file infector infects files of the following file type(s) in network shares, ensuring its propagation across the network:

• .EXE

Backdoor Routine

This file infector opens the following ports:

• TCP Port 11084
• TCP Port 8181

It connects to the following websites to send and receive information:

• http://{BLOCKED}ational-ventur.ru
• http://{BLOCKED}e.2288.org
• http://{BLOCKED}s-locmoczu.ws

Web Browser Home Page and Search Page Modification

This file infector modifies the Internet Explorer Zone Settings.

Information Theft

This file infector steals the following information:

• Windows Product ID
• Drive Volume Serial Number
• OS Version
• User credentials
• Information from Filezilla

NOTES:

It infects executable files with .EXE extensions and files referenced by shortcut (LNK) files. It looks for EXE files that are registered as services, those that are located in the Programs folder in the Start Menu, the user's desktop, and the local Applications Data folder.

It infects files executable files with .EXE extensions and files referenced by shortcut (.LNK) files starting in the Start Menu Programs directory then traverses the directory until it reaches the %Desktop% folder.

Since it infects startup programs, it also serves as the auto-start mechanism of PE_EXPIRO.ZZ.

It also monitors the presence of removable drives. If found, it infects .EXE files in the present removable drive. This serves as its propagation method.

It also searches drives from C:\ to Z:\ which it will also infect found .EXE files. In this way, the drives shared through network will be infected. This also serves as its propagation method.

It executes infected .exe files to perform backdoor routine.

It saves its stolen information using any of the following file names:

• %Application Data%\kf{number}z32.dl
• %Application Data%\dfl{number}z32.dll
• %Application Data%\wsr{number}zt32.dll]