Analysis by: Kathleen Notario

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Infects files

This file infector infects .EXE and .SCR files. It connects to websites to download possibly malicious files.

It also adds mutexes to ensure that only one of its copies runs at any one time.

This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops copies of itself in all removable and physical drives found in the system. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: Varies
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 03 Nov 2010
Payload: Downloads files

Arrival Details

This file infector 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 file infector adds the following mutexes to ensure that only one of its copies runs at any one time:

  • uxJLpe1m
  • Ap1mutx7

Other System Modifications

This file infector adds the following registry keys:

HKEY_CURRENT_USER\Software\{random characters}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UacDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = 1

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
AntiVirusOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
UacDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
UpdatesDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and filename} = {malware path and filename}:*:Enabled:ipsec

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
GlobalUserOffline = 0

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

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

File Infection

This file infector infects the following file types:

  • .EXE
  • .SCR

It avoids infecting files that contain the following strings in their names:

  • DAEMON.
  • NOTEPAD.EXE
  • WINMINE.EXE

Propagation

This file infector drops copies of itself in all removable and physical drives found in the system.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

Note: The order of autorun.inf strings may vary and may contain a combination of uppercase and lowercase letters.
;{garbage characters}
[AutoRun]
;{garbage characters}
shell\explore\command = {random file name}.exe
;{garbage characters}
open = {random file name}.exe
;{garbage characters}
shell\open\command = {random file name}.exe
shell\open\default = 1
;{garbage characters}
shell\autoplay\command = {random file name}.exe
;{garbage characters}

Other Details

This file infector attempts to access the following websites to download files, which are possibly malicious:

  • http://{BLOCKED}.{BLOCKED}.222.206/logos.gif
  • http://{BLOCKED}icoverseas.net/images/xs2.jpg
  • http://{BLOCKED}o.cz/logo.gif
  • http://{BLOCKED}hotel.com/images/logof.gif
  • http://{BLOCKED}mediaproduction.com/images/xs.jpg
  • http://{BLOCKED}e.co.uk/images/xs.jpg
  • http://{BLOCKED}so.com.br/s.jpg
  • http://{BLOCKED}scapeuk.com/xs.jpg
  • http://{BLOCKED}oletarianparty.org/logof.gif
  • http://{BLOCKED}rtltd.com/img/xs.jpg
  • http://{BLOCKED}wing-tomorrow.org/images/s.jpg
  • http://{BLOCKED}rnajd.com/images/logo.gif
  • http://www.{BLOCKED}ine.com/s.jpg

NOTES:

Infected files are detected as PE_SALITY.ER.

This file infector drops the following copy of itself in all physical and removable drives:

  • {Drive Letter}:\{random file name}.{random extension}

Where {random extension} can be any of the following:

  • exe
  • cmd
  • pif

It appends the string below in the abovementioned URLs:

  • ?{randomchars}={randomdigits}

It saves the downloaded files in %User Temp% folder using random file names.

It then infects files in all drives including shared folders. However, it avoids infecting files inside folders containing the string "SYSTEM". It also avoids traversing the windows folder. It also avoids infecting files having file names with more than 250 characters.

  SOLUTION

Minimum Scan Engine: 9.300
VSAPI OPR PATTERN File: 7.589.00
VSAPI OPR PATTERN Date: 03 Nov 2010

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusOverride = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallOverride = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • UacDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • UpdatesDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • AntiVirusDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • AntiVirusOverride = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • FirewallDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • FirewallOverride = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • UacDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
    • UpdatesDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • EnableFirewall = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DoNotAllowExceptions = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DisableNotifications = 1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware path and filename} = {malware path and filename}:*:Enabled:ipsec
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • GlobalUserOffline = 0

Step 4

Delete this registry key

[ 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
    • {random characters}

Step 5

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\Explorer\Advanced
    • From: Hidden = 2
      To: 1

Step 6

Search and delete AUTORUN.INF files created by PE_SALITY.ER-O that contain these strings

[ Learn More ]
;{garbage characters}
[AutoRun]
;{garbage characters}
shell\explore\command = {random filename}.exe
;{garbage characters}
open = {random filename}.exe
;{garbage characters}
shell\open\command = {random filename}.exe
shell\open\default = 1
;{garbage characters}
shell\autoplay\command = {random filename}.exe
;{garbage characters}

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_SALITY.ER-O. 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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