TROJ_ZBOT.ALK

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.

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 drops the following copies of itself into the affected system:

• %System%\twex.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following files:

• %System%\twain32\local.ds
• %System%\twain32\user.ds

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%System%\twex.exe"

(Note: The default value data of the said registry entry is %System%\userinit.exe,.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_USERS\.DEFAULT\Software\
Microsoft\Protected Storage System Provider

HKEY_USERS\.DEFAULT\Software\
Microsoft\Windows\CurrentVersion\
Explorer\{43BF8CD1-C5D5-2230-7BB2-98F22C2B7DC6}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Network
UID = "{machine name}_{random hexadecimal number}"

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}3tr.org/iqato/mix2/cfg.bin