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RTKT_NECURS.RBC
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Encrypted: Yes
In the wild: Yes

Overview


Infection Channel: Dropped by other malware, Downloaded from the Internet

This malware is downloaded by TSPY_ZBOT.YYKE, a malware related to the new UPATRE variant that uses the 'spam within the spam' technique.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

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. It may be dropped by other malware.

It deletes the initially executed copy of itself.

Technical Details


File size: 56,832 bytes
File type: SYS
Memory resident: Yes
Initial samples received date: 20 Mar 2014

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.

It may be dropped by the following malware:

  • TSPY_ZBOT.YYKE

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System%\drivers\{random}.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
DisplayName = "{random}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
ErrorControl = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
Group = "Boot Bus Extender"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
ImagePath = "%System%\drivers\{random}.sys"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
Start = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
Tag = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}
Type = "1"

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random}

Rootkit Capabilities

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

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

This Trojan disables services used by the following companies by modifying its code to return to unsuccessful status:

  • ALWIL Software
  • Agnitum Ltd
  • Anti-Virus
  • Avira GmbH
  • BITDEFENDER LLC
  • Beijing Jiangmin
  • Beijing Rising
  • BitDefender SRL
  • BullGuard Ltd
  • CJSC Returnil Software
  • Check Point Software Technologies Ltd
  • Comodo Inc
  • Comodo Inc
  • Comodo Security Solutions
  • Doctor Web Ltd
  • ESET, spol. s r.o.
  • FRISK Software International Ltd
  • G DATA Software
  • GRISOFT, s.r.o.
  • Immunet Corporation
  • K7 Computing
  • KProcessHacker
  • Kaspersky Lab
  • NovaShield Inc
  • PC Tools
  • Panda Software International
  • Quick Heal Technologies
  • SUNBELT SOFTWARE
  • Sophos Plc
  • Sunbelt Software
  • VirusBuster Ltd
  • WinDefend
  • antimalware

This Trojan disables drivers with the following names by modifying its code to return to unsuccessful status:

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

Solution


Minimum scan engine: 9.700
First VSAPI Pattern File: 10.674.06
First VSAPI Pattern Release Date: 20 Mar 2014
VSAPI OPR Pattern Version: 10.675.00
VSAPI OPR Pattern Release Date: 20 Mar 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 malware/grayware files that dropped/downloaded RTKT_NECURS.RBC

Step 3

Scan your computer with your Trend Micro product and note files detected as RTKT_NECURS.RBC

Step 4

Restart in Safe Mode

[ Learn more ]

Step 5

Delete this registry key

[ 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\CurrentControlSet\Services
    • {random}

Step 6

Search and delete files detected as RTKT_NECURS.RBC

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

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RTKT_NECURS.RBC. 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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Analysis By: Rika Joi Gregorio
Modified By: Jaime Benigno Reyes

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