WORM_NORPO.B
Backdoor:Win32/Kelihos (Microsoft), Trojan-PSW.Win32.Tepfer.ppak (Kaspersky)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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 into all the removable drives connected to an affected system.
It modifies the Internet Explorer Zone Settings.
TECHNICAL DETAILS
1,121,933 bytes
EXE
Yes
10 Sep 2013
Arrival Details
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NetworkChecker = "{Original File Path}\porn.exe"
Propagation
This worm drops copies of itself into all the removable drives connected to an affected system.
Web Browser Home Page and Search Page Modification
This worm modifies the Internet Explorer Zone Settings.
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}g.cc/
- http://{BLOCKED}op.com
- http://da5df6.{BLOCKED}j.com/calc.exe
NOTES:
It hides the original copy of itself after renaming it to "porn.exe".
SOLUTION
9.300
10.290.03
16 Aug 2013
10.291.00
17 Aug 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
Step 3
Delete this registry value
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\CurrentVersion\Run
- NetworkChecker = "{Original File Path}\porn.exe"
- NetworkChecker = "{Original File Path}\porn.exe"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_NORPO.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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