WORM_CONUS.M
Worm:Win32/Conustr.A (Microsoft), Trojan.Win32.Vague.bn (Kaspersky)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
TECHNICAL DETAILS
159,744 bytes
EXE
No
30 Jul 2018
Installation
This Worm drops the following copies of itself into the affected system and executes them:
- %User Temp%\conhost.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
It drops the following files:
- %User Temp%\ppxxxx
- %User Temp%\must.bat
- %User Temp%\winword4.doc
- %User Temp%\WPDNSE\E73D7C2F.NLS
- {Removable Drive}:\Recycler\E73D7C2F.NLS
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
It creates the following folders:
- %User Temp%\WPDNSE
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)
Autostart Technique
This Worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = %User Temp%\conhost.exe
Other System Modifications
This Worm adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
exefile
NeverShowExt = {blank]
HKEY_LOCAL_MACHINE\Software\Google\
Update
LastInstallerResultUIString = "Installation failed due to unspecified error. If Google Chrome is currently running, please close it and try again."
Propagation
This Worm creates the following folders in all removable drives:
- {Removable Drive}:\Recycler
It drops the following copy(ies) of itself in all removable drives:
- {Removable Drive}:\{Folder Name}.exe
- {Removable Drive}:\Recycler\Dcfly.exe
SOLUTION
9.850
14.420.05
03 Aug 2018
14.421.00
04 Aug 2018
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- Load = "%User Temp%\conhost.exe"
- Load = "%User Temp%\conhost.exe"
- In HKEY_LOCAL_MACHINE\Software\Google\Update
- LastInstallerResultUIString = "Installation failed due to unspecified error. If Google Chrome is currently running, please close it and try again."
- LastInstallerResultUIString = "Installation failed due to unspecified error. If Google Chrome is currently running, please close it and try again."
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\exefile
- NeverShowExt = {blank}
- NeverShowExt = {blank}
Step 4
Search and delete these folders
- %User Temp%\WPDNSE
- {Removable Drive}:\Recycler
Step 5
Search and delete this file
- %User Temp%\ppxxxx
- %User Temp%\must.bat
- %User Temp%\winword4.doc
- %User Temp%\WPDNSE\E73D7C2F.NLS
- {Removable Drive}:\Recycler\E73D7C2F.NLS
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_CONUS.M. 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 the following Trend Micro Support pages for more information:
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