TROJ_FAKEAV.ESY

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It may be unknowingly downloaded by a user while visiting malicious websites.

It connects to certain websites to send and receive information.

It installs a fake antivirus/antispyware software. 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. When users agree to buy the software, it connects to a certain URL.

File Size: 286,720 bytes

Memory Resident: Yes

Initial Samples Received Date: 10 Dec 2011

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

Installation

This Trojan drops the following copies of itself into the affected system:

%Application Data%\{three random characters}.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 drops the following file(s)/component(s):

%Application Data%\2mib87egb1c6o3
%User Temp%\2mib87egb1c6o3
%System Root%\Documents and Settings\All Users\Application Data%\2mib87egb1c6o3

(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.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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
{random numbers} = %Application Data%\{malware file name}.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\.exe\DefaultIcon

HKEY_CLASSES_ROOT\.exe\shell

HKEY_CLASSES_ROOT\.exe\shell\
open

HKEY_CLASSES_ROOT\.exe\shell\
open\command

HKEY_CLASSES_ROOT\.exe\shell\
runas

HKEY_CLASSES_ROOT\.exe\shell\
runas\command

It adds the following registry entries:

HKEY_CLASSES_ROOT\.exe\DefaultIcon
(default) = %1

HKEY_CLASSES_ROOT\.exe\shell\
open\command
(default) = {malware path and file name} -a "%1" %*

HKEY_CLASSES_ROOT\.exe\shell\
open\command
IsolatedCommand = "%1" %*

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
(default) = "%1" %*

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
IsolatedCommand = "%1" %*

HKEY_CLASSES_ROOT\exefile
Content Type = application/x-msdownload

HKEY_CLASSES_ROOT\exefile\shell\
open\command
IsolatedCommand = "%1" %*

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DoNotAllowExceptions = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DisableNotifications = "1"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"