PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 253,440 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 05 Aug 2016

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\7F32CAE8D6821FD50DE571C40A8342ACAF85_stub.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
Description = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
Running = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
UName = "3C372D8"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
conn = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
hend = "927c"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
DisplayName = "Net.Udp Listener Adapter"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
ImagePath = "{malware path and file name}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator
Type = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator\Enum
0 = "Root\LEGACY_NetUdpActivator\0000"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator\Enum
Count = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator\Enum
NextInstance = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\NetUdpActivator\Security
Security = "{random values}"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\nuapid

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}91.45

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.8

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

Delete this registry value

[ Learn More ]

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\SYSTEM\ControlSet001\Services\NetUdpActivator
    • Description = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • Running = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • UName = "3C372D8"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • conn = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • hend = "927c"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • DisplayName = "Net.Udp Listener Adapter"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • ImagePath = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • ObjectName = "LocalSystem"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator
    • Type = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator\Enum
    • 0 = "Root\LEGACY_NetUdpActivator\0000"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator\Enum
    • Count = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator\Enum
    • NextInstance = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetUdpActivator\Security
    • Security = "{random values}"

Step 3

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System Root%\nuapid

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DYNAMER.XXXV. 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.

Step 5

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\7F32CAE8D6821FD50DE571C40A8342ACAF85_stub.exe


Did this description help? Tell us how we did.