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BKDR_NANOCOR.CR

May 11, 2016
 ALIASES:

Backdoor:MSIL/Noancooe.C (Microsoft)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

321,024 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Feb 2016

Arrival Details

This backdoor 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 backdoor drops the following files:

  • %Application Data%\Microsoft\Blend\14.0\FeedCache\nvSCPAPISrv.exe - copy of itself
  • %Application Data%\Microsoft\Blend\14.0\FeedCache\PerfWatson.exe - component used to load the malware copy. This is also detected as BKDR_NANOCOR.CR

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%Application Data%\Microsoft\Blend\14.0\FeedCache\PerfWatson.exe"

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}015.{BLOCKED}nkiller.com:1617
  • {BLOCKED}a.{BLOCKED}nkiller.com:1617

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.326.04

FIRST VSAPI PATTERN DATE:

08 Feb 2016

VSAPI OPR PATTERN File:

12.327.00

VSAPI OPR PATTERN Date:

09 Feb 2016

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

[ Learn More ]

Step 4

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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • Load = "%Application Data%\Microsoft\Blend\14.0\FeedCache\PerfWatson.exe"

Step 5

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