TROJ_FAKEAV.CAC

It drops component files that Trend Micro also detects as TROJ_FAKEAV.CAC.

This Trojan may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

It executes then deletes itself afterward.

It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.

Arrival Details

This Trojan may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following component file(s):

• %Application Data%\{random file name}.exe - also detected as TROJ_FAKEAV.CAC
• %Application Data%\mbnYpfcsksFIKuQ.dll - also detected as TROJ_FAKEAV.CAC

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It drops the following copies of itself into the affected system:

• %Application Data%\irRCpVinxLWrQQS.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It executes then deletes itself afterward.

It displays the following fake error messages:

A hard drive error occured while starting the application.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
irRCpVinxLWrQQS.exe = "%Application Data%\irRCpVinxLWrQQS.exe"

Other System Modifications

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

HKEY_CURRENT_USER\Software
12B79064-EB17-4f82-9DFE-B975BD26D1DC =

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = "/{hq:/s`s:/ogn:/uyu:/dyd:/c`u:/bnl:/ble:/sdf:/lrh:/iul:/iulm:/fhg:/clq:/kqf:/`wh:/lqf:/lqdf:/lnw:/lq2:/l2t:/v`w:/rbs:"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
SaveZoneInformation = 1

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Download
CheckExeSignatures = "no"

(Note: The default value data of the said registry entry is "yes".)

Rogue Antivirus Routine

This Trojan displays the following fake alerts:

It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.