Analysis by: Rhena Inocencio
ALIASES:

Trojan:WinNT/Necurs.A (Microsoft), Rootkit.Win32.Necurs.kl (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 33,024 bytes
File Type: SYS
Memory Resident: Yes
Initial Samples Received Date: 09 Jun 2014
Payload: Compromises system security, Disables drivers

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_NECURS.BGTI
  • TROJ_NECURS.BGTJ
  • TROJ_NECURS.TENJ
  • TROJ_NECURS.TENI

Rootkit Capabilities

This Trojan is used by other malware for its rootkit functionalities.

NOTES:

It disables services used by the following companies by modifying its code to return unsuccessful status.

  • Alwil Software
  • Agnitum Ltd
  • Anti-Virus
  • Avira
  • AVG
  • Bitfefender
  • Beijing Jiangmin
  • Beijing Rising
  • BullGuard Ltd
  • CJSC Returnil Software
  • Check Point Software Technologies Ltd
  • Comodo Inc
  • Dr. Web
  • ESET
  • FRISK Software International
  • G Data Software
  • Immunet Corporation
  • K7 Computing
  • KProcessHacker
  • Kaspersky Lab
  • NovaShield Inc.
  • PC Tools
  • Panda Software International
  • Quick Heal Technologies Pvt. Ltd
  • Sunbelt Software
  • Sophos
  • Symantec
  • VirusBuster Ltd

It disables drivers with the following name by modifying its code to return unsuccessful status.

  • eraser.sys
  • SRTSP.sys
  • SRTSPIT.sys
  • SRTSP64.SYS
  • a2gffx86.sys
  • a2gffx64.sys
  • a2gffi64.sys
  • a2acc.sys
  • a2acc64.sys
  • mbam.sys
  • eamonm.sys
  • MaxProtector.sys
  • SDActMon.sys
  • tmevtmgr.sys
  • tmpreflt.sys
  • vcMFilter.sys
  • drivesentryfilterdriver2lite.sys
  • mpFilter.sys
  • PSINPROC.SYS
  • PSINFILE.SYS
  • amfsm.sys
  • amm8660.sys
  • amm6460.sys
  • caavFltr.sys
  • ino_fltr.sys
  • avmf.sys
  • PLGFltr.sys
  • AshAvScan.sys
  • csaav.sys
  • SegF.sys
  • eeyehv.sys
  • eeyehv64.sys
  • NovaShield.sys
  • BdFileSpy.sys
  • tkfsft.sys
  • tkfsft64.sys
  • tkfsavxp.sys
  • tkfsavxp64.sys
  • SMDrvNt.sys
  • ATamptNt.sys
  • V3Flt2k.sys
  • V3MifiNt.sys
  • V3Ift2k.sys
  • V3IftmNt.sys
  • ArfMonNt.sys
  • AhnRghLh.sys
  • AszFltNt.sys
  • OMFltLh.sys
  • V3Flu2k.sys
  • vcdriv.sys
  • vcreg.sys
  • vchle.sys
  • NxFsMon.sys
  • AntiLeakFilter.sys
  • NanoAVMF.sys
  • shldflt.sys
  • nprosec.sys
  • nregsec.sys
  • issregistry.sys
  • THFilter.sys
  • pervac.sys
  • avgmfx86.sys
  • avgmfx64.sys
  • avgmfi64.sys
  • avgmfrs.sys
  • fortimon2.sys
  • fortirmon.sys
  • fortishield.sys
  • savonaccess.sys
  • OADevice.sys
  • pwipf6.sys
  • EstRkmon.sys
  • EstRkr.sys
  • dwprot.sys
  • Spiderg3.sys
  • STKrnl64.sys
  • UFDFilter.sys
  • SCFltr.sys
  • fildds.sys
  • fsfilter.sys
  • fpav_rtp.sys
  • cwdriver.sys
  • Rtw.sys
  • HookSys.sys
  • snscore.sys
  • ssvhook.sys
  • strapvista.sys
  • strapvista64.sys
  • sascan.sys
  • savant.sys
  • vradfil2.sys
  • fsgk.sys
  • PCTCore64.sys
  • PCTCore.sys
  • ikfilesec.sys
  • ZxFsFilt.sys
  • antispyfilter.sys
  • PZDrvXP.sys
  • ggc.sys
  • catflt.sys
  • kmkuflt.sys
  • mfencoas.sys
  • mfehidk.sys
  • cmdguard.sys
  • K7Sentry.sys
  • nvcmflt.sys
  • issfltr.sys
  • AVCKF.SYS
  • bdfsfltr.sys
  • bdfm.sys
  • AVC3.SYS
  • aswmonflt.sys
  • HookCentre.sys
  • PktIcpt.sys
  • MiniIcpt.sys
  • avgntflt.sys
  • klbg.sys
  • kldback.sys
  • kldlinf.sys
  • kldtool.sys
  • klif.sys
  • lbd.sys
  • rvsmon.sys
  • ssfmonm.sys
  • KmxAgent.sys
  • KmxAMRT.sys
  • KmxAMVet.sys
  • KmxStart.sys
  • ahnflt2k.sys
  • AhnRec2k.sys
  • AntiyFW.sys
  • v3engine.sys
  • Vba32dNT.sys
  • kprocesshacker.sys

It causes the system to crash when running on a virtual machine.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.852.01
FIRST VSAPI PATTERN DATE: 09 Jun 2014

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

Remove the malware/grayware file dropped/downloaded by RTKT_NECURS.AH. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    • TROJ_NECURS.BGTI
    • TROJ_NECURS.BGTJ
    • TROJ_NECURS.TENJ
    • TROJ_NECURS.TENI

Step 3

Scan your computer with your Trend Micro product to delete files detected as RTKT_NECURS.AH. 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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