WORM_SMALL.ECD
Downloader (Symantec); Backdoor:Win32/Hupigon.EX (Microsoft); PAK:PE_Patch (Kaspersky); Generic BackDoor!dlk (Mcafee); W32/BackDoor.DLK!tr (Fortinet)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This worm connects to a random IP address and takes advantage of the vulnerability MS08-067 (Vulnerability in Server Service Could Allow Remote Code Execution). It may also exploit a vulnerability in Microsoft Jet Database Engine (MS08-28) by connecting to port 1433 using certain user names and passwords.
If the exploit is successful, it invokes a shellcode to download and execute files from an FTP server.
This worm may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.
TECHNICAL DETAILS
Arrival Details
This worm may be downloaded by other malware/grayware/spyware from remote sites.
It may be dropped by other malware.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This worm drops the following files:
- %System Root%\Tcpz-x86.sys
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
NOTES:
Download Routine
It connects to a random IP address and takes advantage of the vulnerability MS08-067 (Vulnerability in Server Service Could Allow Remote Code Execution). It may also exploit a vulnerability in Microsoft Jet Database Engine (MS08-28) by connecting to port 1433 using the following user names and passwords:
- sa
- ic
- zxm1987
- as
- sql
- 123456
- hjs
- pos
- anypass
- sasa
- kingdee
- 8888
For more information on the aforementioned vulnerabilities, please see the following pages:
If the exploit is successful, it invokes a shellcode to download and execute files from an FTP server:
- to.{BLOCKED}a.com
Currently, Trend Micro detects the downloaded files as:
- BKDR_VENIK.AE
- BKDR_RBOT.SMB
As a result, the malicious routines of the said files are also exhibited in the system.
It registers its component as a service by creating the following registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpz-x86
ImagePath = "%SystemRoot%\Tcpz-x86.sys"
It connects to the following URL:
- http://net.{BLOCKED}a.com/it.asp?intTimes={number}
SOLUTION
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 3
Identify and terminate files detected as WORM_SMALL.ECD
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
Restart in Safe Mode, and then delete this registry key
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.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpz-x86
Step 5
Search and delete this file
- %System Root%\Tcpz-x86.sys
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_SMALL.ECD. 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.
Step 7
Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.
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