BKDR_SYKIPOT.SM

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

Arrival Details

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

It may be dropped by the following malware:

• TROJ_PIDIEF.EGG

Installation

This backdoor drops the following files:

• %User Profile%\Local Settings\gtpretty.tmp - contains commands from the C&C server
• %User Profile%\Local Settings\gdtpretty.tmp - contains the decrypted commands from the C&C server
• %User Profile%\Local Settings\ptpretty.tmp - log file
• %User Profile%\Local Settings\pdtpretty.tmp - encrypted log file

(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 component file(s):

• %User Profile%\Local Settings\WSE4EF1.TMP - also detected as BKDR_SYKIPOT.SM

(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

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

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"

NOTES:
The file pdtpretty.tmp contains the following information:

• process injected
• adapter information (from ipconfig /all)
• started windows services
• active network connections
• running processes
• the result of the command, dir c:\*.url /s
• system information (OS, processor, bios version, time zone, memory, etc)
• contents of boot.ini

It then encrypts this file and saves it as ptpretty.tmp. This is later on sent to the server upon initial connection:

• https://www.{BLOCKED}likeher.com/asp/kys_allow_get.asp?name=getkys.kys&hostname={computer name}-{ip address}-pretty20111122

It uses http://www.yahoo.com/ as its referrer.

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

• cmd: remote command-prompt commands
• door: execute subcommands:
  • run executes a command using WinExec
  • reboot restarts the computer
  • kill terminates a process
  • process list all processes
  • shell do nothing
• time: indicate next connection time
• getfile: downloads files
• putfile: upload files