WORM64_DISTTRACK.SM
Windows
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
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 uses Windows Task Scheduler to create a scheduled task that executes the dropped copy.
It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
TECHNICAL DETAILS
Arrival Details
This worm may arrive via network shares.
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%\ntssrvr64.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following component file(s):
- %Temp%\key8854321.pub ← contains Public Key
- %System%\Drivers\drdisk.sys
(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops and executes the following files:
- %System%\netinit.exe ← used for reporting (damaged)
- %System%\{random filename}.exe ← used to wipe MBR (WORM64_DISTTRACK.SM)
- where {random filename} is any of the following:
- caclsrv
- certutl
- clean
- ctrl
- dfrag
- dnslookup
- dvdquery
- event
- findfile
- gpget
- ipsecure
- iissrv
- msinit
- ntfrsutil
- ntdsutl
- power
- rdsadmin
- regsys
- sigver
- routeman
- rrasrv
- sacses
- sfmsc
- smbinit
- wcscript
- ntnw
- netx
- fsutl
- extract
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It uses Windows Task Scheduler to create a scheduled task that executes the dropped copy.
Propagation
This worm drops copies of itself in the following shared folders:
- ADMIN$
- C$\WINDOWS
- D$\WINDOWS
- E$\WINDOWS
Dropping Routine
This worm executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
Other Details
This worm adds and runs the following services:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
ImagePath = "%System%\ntssrvr64.exe LocalService" or "{malware path and filename} LocalService"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
DisplayName = "Microsoft Network Realtime Inspection Service"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
DependOnService = "RpcSs"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
DependOnGroup = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtsSrv
Description = "Helps guard against time change attempts targeting known and newly discovered vulnerabilities in network time protocols"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\LanmanWorkstation
DependOnGroup = ""
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\LanmanWorkstation
DependOnService = NtsSrv
NOTES:
The component DRDISK.SYS enables this malware to overwrite all disk partitions with a JPEG image file. This renders the system unusable after reboot.
This malware overwrites files with the same JPEG image file used for the disk corruption. The overwriten file retains its file size, thus, the image file becomes corrupted. The files that it overwrites are the following:
- All files in C:\Documents and Settings containing the words "download" and "document" in the file name.
- All files in C:\Users containing the following words in the file name:
- download
- document
- picture
- video
- music
- All files in C:\Documents and Settings and C:\Users containing the word "desktop" in the file name.
- All files in C:\Windows\System32\Drivers.
- All files in C:\Windows\System32\Config containing the word "systemprofile" in the file name.
It also creates the file %Windows%\inf\netimm173.pnf. The said file contains the number of files to be compromised. It is used for reporting to its C&C server.
The 'netinit.exe' is responsible for the following:
- Sending information about the infection back to the server.
- It is capable of receiving files from the remote server and execute it on the affected system.
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
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
Restart in Safe Mode
Step 4
Delete this registry key
=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\SYSTEM\CurrentControlSet\Services
- NtsSrv
- NtsSrv
Step 5
Delete these 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\SYSTEM\CurrentControlSet\Services\LanmanWorkstation
- DependOnGroup = ""
- DependOnGroup = ""
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation
- DependOnService = NtsSrv
- DependOnService = NtsSrv
Step 6
Search and delete these files
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM64_DISTTRACK.SM. 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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