WORM_RENOCIDE.GK
Worm:Win32/Renocide (Microsoft), W32.Harakit (Symantec), Worm.Win32.AutoIt.qx (Kaspersky), Mal/Renocide-C Mal/Renocide-A (Sophos)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. It arrives by accessing affected shared networks. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It propagates via shared networks and drops copies of itself into available networks. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It modifies the Internet Explorer Zone Settings.
TECHNICAL DETAILS
Arrival Details
This worm arrives via removable drives.
It arrives by accessing affected shared networks.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This worm drops the following copies of itself into the affected system and executes them:
- %System%\csrcs.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It drops the following files:
- %System%\autorun.inf
- %System%\cftm.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This worm modifies the following registry entry(ies) to enable its automatic execution at every system startup:
HKLM\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "Explorer.exe csrcs.exe"
(Note: The default value data of the said registry entry is Explorer.exe.)
It creates the following registry entries to enable automatic execution of dropped component at every system startup:
HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
csrcs = "%System%\csrcs.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
It modifies the following registry entries:
HKCU\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
HKCU\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
HKCU\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
It also creates the following registry entry(ies) as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
dreg = {random data}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
exp1 = {random data}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
fix = {random data}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
ilop = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
regexp = {random data}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DRM\amty
eggol = "0"
Propagation
This worm propagates via shared networks and drops copies of itself into available networks.
It drops the following copy of itself in all physical and removable drives:
- {drive letter}:\{random filename}.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
;{random characters}
[AutoRun]
;{random characters}
open={random filename}.exe
;{random characters}
shell\open\Command={random filename}.exe
;{random characters}
shell\open\Default=1
;{random characters}
;{random characters}
shell\explore\Command={random filename}.exe
;{random characters}
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:
- {BLOCKED}y.{BLOCKED}q.com
- {BLOCKED}s.{BLOCKED}p.jp:6854/pro.gif
- www.{BLOCKED}yip.com
- {BLOCKED}p.{BLOCKED}s.org
- http://{BLOCKED}.{BLOCKED}.19.236:6854
- http://{BLOCKED}.{BLOCKED}.19.238:4900
- http://{BLOCKED}.{BLOCKED}.19.237:5200
- http://{BLOCKED}.{BLOCKED}.19.236:88
- http://{BLOCKED}.{BLOCKED}.19.238:5300
- http://{BLOCKED}.{BLOCKED}.19.236:5100
SOLUTION
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
Identify and delete files detected as WORM_RENOCIDE.GK using either the Startup Disk or Recovery Console
Step 3
Restart in Safe Mode
Step 4
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Shell = "Explorer.exe csrcs.exe"
To: Shell = "Explorer.exe"
- From: Shell = "Explorer.exe csrcs.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = "1"
- From: Hidden = "2"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: SuperHidden = "0"
To: SuperHidden = "1"
- From: SuperHidden = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = "0"
To: ShowSuperHidden = "1"
- From: ShowSuperHidden = "0"
Step 5
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\policies\Explorer\Run
- csrcs = “%System%\csrcs.exe”
- csrcs = “%System%\csrcs.exe”
Step 6
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\SOFTWARE\Microsoft\DRM\amtyStep 7
Search and delete these files
- %System%\cftm.exe
Step 8
Search and delete AUTORUN.INF files created by WORM_RENOCIDE.GK that contain these strings
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_RENOCIDE.GK. 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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