Analysis by: Kerstan Josef Navarro
 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:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  TECHNICAL DETAILS

File Size: 13753 bytes
Memory Resident: Yes
Initial Samples Received Date: 18 Jul 2013

Installation

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

  • %Program Files%\Common Files\longf.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

It drops the following files:

  • %System%\drivers\etc\hosts.ics

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\Run
rdchelp = "%Program Files%\Common Files\longf.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
rdchelp = "%Program Files%\Common Files\longf.exe"

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = "0"

HOSTS File Modification

This backdoor overwrites the HOSTS file in the following locations:

  • %System%\drivers\etc\host (On Windows 2000, XP, and Server 2003)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.158.03
FIRST VSAPI PATTERN DATE: 16 Jul 2013
VSAPI OPR PATTERN File: 10.159.00
VSAPI OPR PATTERN Date: 16 Jul 2013

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\Windows\Run
    • rdchelp = "%Program Files%\Common Files\longf.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • rdchelp = "%Program Files%\Common Files\longf.exe"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System
    • DisableCMD = "0"

Step 4

Search and delete this file

[ Learn More ]
There may be some 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.
  • %Program Files%\Common Files\longf.exe
  • %System%\drivers\etc\hosts.ics

Step 5

Remove these strings added by the malware/grayware/spyware in the HOSTS file

[ Learn More ]
    • 60.148.70.164 OmOney.kbstar.COM
    • 60.148.70.164 ibz.nOnghyup.COM
    • 60.148.70.164 bizbAnK.shinhan.COM
    • 60.148.70.164 kiup.ibk.cO.Kr
    • 60.148.70.164 Online.keb.cO.Kr
    • 60.148.70.164 ObAnK.kbstar.COM
    • 60.148.70.164 bAnKing.nOnghyup.COM
    • 60.148.70.164 pib.wOOribAnK.COM
    • 60.148.70.164 bAnKing.shinhan.COM
    • 60.148.70.164 mybAnK.ibk.cO.Kr
    • 60.148.70.164 ibs.kfcc.cO.Kr
    • 60.148.70.164 ebAnK.keb.cO.Kr
    • 60.148.70.164 ib.scfirstbAnK.COM
    • 60.148.70.164 scfirstbAnK.COM
    • 60.148.70.164 kbstar.COM
    • 60.148.70.164 nOnghyup.COM
    • 60.148.70.164 wOOribAnK.COM
    • 60.148.70.164 shinhan.COM
    • 60.148.70.164 ibk.cO.Kr
    • 60.148.70.164 hanabAnK.COM
    • 60.148.70.164 kfcc.cO.Kr
    • 60.148.70.164 keb.cO.Kr
    • 60.148.70.164 epOstbAnK.gO.Kr
    • 60.148.70.164 citibAnK.cO.Kr
    • 60.148.70.164 standardchartered.cO.Kr
    • 60.148.70.164 OpEn.kbstar.COM
    • 60.148.70.164 OpEn.nOnghyup.COM
    • 60.148.70.164 u.wOOribAnK.COM
    • 60.148.70.164 OpEn.shinhan.COM
    • 60.148.70.164 OpEn.ibk.cO.Kr
    • 60.148.70.164 OpEn.hanabAnK.COM
    • 60.148.70.164 OpEn.kfcc.cO.Kr
    • 60.148.70.164 OpEn.keb.cO.Kr
    • 60.148.70.164 OpEn.epOstbAnK.gO.Kr
    • 60.148.70.164 OpEn.citibAnK.cO.Kr
    • 60.148.70.164 OpEn.standardchartered.cO.Kr
    • 60.148.70.164 wWW.kbstar.COM
    • 60.148.70.164 wWW.nOnghyup.COM
    • 60.148.70.164 wWW.wOOribAnK.COM
    • 60.148.70.164 wWW.shinhan.COM
    • 60.148.70.164 wWW.ibk.cO.Kr
    • 60.148.70.164 wWW.hanabAnK.COM
    • 60.148.70.164 wWW.kfcc.cO.Kr
    • 60.148.70.164 wWW.keb.cO.Kr
    • 60.148.70.164 wWW.epOstbAnK.gO.Kr
    • 60.148.70.164 wWW.citibAnK.cO.Kr
    • 60.148.70.164 wWW.standardchartered.cO.Kr
    • 60.148.70.164 NAVer.COM
    • 60.148.70.164 daUM.net
    • 60.148.70.164 hanmail.net
    • 60.148.70.164 wWW.NAVer.COM
    • 60.148.70.164 wWW.daUM.net
    • 60.148.70.164 wWW.hanmail.net

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_FLYAGEN.HM. 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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