WORM_MORTO.SMB

August 19, 2015
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

Worm:Win32/Morto.J (Microsoft); W32/Morto.P!tr (Fortinet); W32/Morto.dll.e (McAfee); Mal/Morto-A (Sophos); a variant of Win32/Morto.Q worm (ESET-NOD32); W32.Morto!gen2 (Symantec); Worm.Win32.Morto.ab (v) (Sunbelt); W32/Morto.F.gen!Eldorado (generic, not disinfectable) (F-Prot); Worm.Win32.Morto (Ikarus);

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • 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 requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size:

14,848 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

13 Aug 2015

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.

Other Details

This worm requires its main component to successfully perform its intended routine.

NOTES:

This worm attempts to open the file \\TsClient\A\Moto if it is running in RUNDLL32.DLL. If successful, it executes the bytes in the file \\TsClient\A\Moto. It then forcefully logs the user off.

If it is not executing in running in RUNDLL32.DLL, it reads the following registry entry:

  • HKEY_LOCAL_MACHINE\SYSTEM\Wpa
    md = "{random values}"

    • It then executes the returned random values.

      SOLUTION

    Minimum Scan Engine:

    9.750

    FIRST VSAPI PATTERN FILE:

    11.738.05

    FIRST VSAPI PATTERN DATE:

    18 Jun 2015

    VSAPI OPR PATTERN File:

    11.739.00

    VSAPI OPR PATTERN Date:

    19 Jun 2015

    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

    Scan your computer with your Trend Micro product and note files detected as WORM_MORTO.SMB

    Step 3

    Restart in Safe Mode

    [ Learn More ]

    Step 4

    Search and delete the file detected as WORM_MORTO.SMB

    [ Learn More ]
    Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

    Step 5

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_MORTO.SMB. 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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