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BKDR_SYKIPOT.B
Malware type: Backdoor
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
Encrypted: No
In the wild: Yes

Overview


This backdoor may be unknowingly downloaded by a user while visiting malicious websites. It may be dropped by other malware.

It deletes the initially executed copy of itself.

Technical Details


File size: 40,960 bytes
File type: EXE
Memory resident: Yes
Initial samples received date: 07 Dec 2011
Payload: Connects to URLs/IPs

Arrival Details

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

It may be dropped by the following malware:

  • TROJ_PIDIEF.EGG

Installation

This backdoor drops the following files:

  • %User Profile%\Local Settings\pdtpretty.tmp
  • %User Profile%\Local Settings\ptpretty.tmp
  • %User Profile%\Local Settings\WSE4EF1.TMP - also detected as BKDR_SYKIPOT.B

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

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

  • %User Profile%\Local Settings\pretty.exe

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

Its DLL component is injected to the following process(es):

  • outlook.exe
  • iexplore.exe
  • firefox.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
office = "%User Profile%\Local Settings\pretty.exe"

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

It creates the file %User Profile%\Local Settings\pdtpretty.tmp, which contains the following information:

  • Active network connection
  • Adapter information (from ipconfgi /all)
  • Contents of boot.ini
  • Process injected
  • Result of the command dir c:\*.url /s
  • Running processes
  • Started Windows services
  • System information (OS, processor, bios version, time zone, memory, etc.)

It then encrypts the created file and saves it as %User Profile%\Local Settings\ptpretty.tmp. This is later on sent to the following server upon initial connection:

  • https://www.{BLOCKED}her.com/asp/kys_allow_get.asp?name=getkys.kys&hostname=%7bhostname%7d-%7bip%7d-pretty20111122

If the connection is successful, it may perform the following routines depending on the server's reply:

  • Execute files
  • Perform shell commands
  • Reboot system
  • Terminate processes
  • Upload and download files

Solution


Minimum scan engine: 9.200

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

Remove the malware/grayware file that dropped/downloaded BKDR_SYKIPOT.B

Step 3

Restart in Safe Mode

[ Learn more ]

Step 4

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
    • office = %User Profile%\Local Settings\pretty.exe

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.
  • %User Profile%\Local Settings\pdtpretty.tmp
  • %User Profile%\Local Settings\ptpretty.tmp

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SYKIPOT.B. 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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Analysis By: Erika Bianca Mendoza

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