TROJ_ZCLICK.YYJC

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.

It deletes itself after execution.

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:

• %Application Data%\{random foldername}\{random filename 1}.exe
• %System%\{random filename 2}.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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random foldername}\{random filename 1}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random foldername}\{random filename 1}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\{random key 1}

HKEY_CURRENT_USER\SOFTWARE\{random key 1}

HKEY_LOCAL_MACHINE\SOFTWARE\{random key 2}

HKEY_CURRENT_USER\SOFTWARE\{random key 2}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\{random key 1}
License = "444"

HKEY_CURRENT_USER\Software\{random key 1}
License = "444"

HKEY_LOCAL_MACHINE\SOFTWARE\{random key 2}
Tasks = "{hex values}"

HKEY_CURRENT_USER\Software\{random key 2}
Tasks = "{hex values}"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_BROWSER_EMULATION
{random filename 1}.exe = "11001"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random number 1}
DisplayName = "Security Center Server - {random number 1}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random number 1}
ImagePath = "%Windows%\Tasks\Security Center Update - {random number 1}.job"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SafeBoot

Dropping Routine

This Trojan drops the following files:

• %Windows%\Tasks\Security Center Update - {random number 1}.job

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}pyallow.su/
• http://{BLOCKED}madeeasy.su
• http://{BLOCKED}ydaypp.ru/
• http://{BLOCKED}urmansk.su/
• http://{BLOCKED}enpiano.ru/
• http://{BLOCKED}redtired.com/

It deletes itself after execution.