TROJ_FAKESYSD.AE

 Analysis by: Christopher Daniel So

 ALIASES:

Trojan:Win32/FakeSysdef (Microsoft), Mal/FakeAV-EA (Sophos), FraudTool.Win32.FakeAV.hdd (Sunbelt), W32/Krap.AON!tr (Fortinet), Trojan-Downloader.Win32.Murlo (Ikarus)

 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats. As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

387,072 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

07 Jan 2011

Payload:

Connects to URLs/Ips

Arrival Details

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

Installation

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

  • %System Root%\Documents and Settings\All Users\Application Data\{random file name}.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It drops the following files:

  • %Start Menu%\Programs\Easy Scan\Easy Scan.lnk
  • %Start Menu%\Programs\Easy Scan\Uninstall Easy Scan.lnk
  • %Desktop%\Easy Scan.lnk
  • %System Root%\Documents and Settings\All Users\Application Data\{random file name}

(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.. %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop 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.)

It creates the following folders:

  • %Start Menu%\Programs\Easy Scan

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

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 string} = "%System Root%\Documents and Settings\All Users\Application Data\{random file name}.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
CurrentVersion\Internet Settings
WarnOnZoneCrossing = 0

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Use FormSuggest = "Yes"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1601 = 0

(Note: The default value data of the said registry entry is 1.)

Download Routine

This Trojan connects to the following malicious URLs:

  • http://{BLOCKED}te.org/dfrg/dfrg
  • http://{BLOCKED}te.org/dfrg/dfrgr
  • http://{BLOCKED}middle.org/dfrg/dfrg
  • http://{BLOCKED}middle.org/dfrg/dfrgr

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

7.752.11

VSAPI PATTERN Date:

07 Jan 2011

VSAPI PATTERN Date:

1/7/2011 12:00:00 AM

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and terminate files detected as TROJ_FAKESYSD.AE

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random string}=%System Root%\Documents and Settings\All Users\Application Data\{random file name}.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\CurrentVersion\Internet Settings
    • WarnOnZoneCrossing=0
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • Use FormSuggest=Yes

Step 4

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • From: 1601=0
      To: 1601=1

Step 5

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result. %Desktop%\Easy Scan.lnk
%System Root%\Documents and Settings\All Users\Application Data\{random file name}

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result. %Start Menu%\Programs\Easy Scan

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKESYSD.AE. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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