RTKT_NECURS.BGSH

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 does not have any propagation routine.

It does not have any backdoor routine.

It does not have any downloading capability.

It does not have any information-stealing capability.

It deletes the initially executed copy of itself.

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.YUNKC

Installation

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

• %System%\drivers\{random filename}.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\
Enum\Root\LEGACY_{malware filename}
NextInstance = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Service = "{malware filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Legacy = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
ConfigFlags = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
Class = "LegacyDriver"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
ClassGUID = "{GUID}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000
DeviceDesc = "{malware filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000\Control
*NewlyCreated* = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000\Control
ActiveService = "{malware filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}
NextInstance = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
Service = "{random filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
Legacy = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
ConfigFlags = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
Class = "LegacyDriver"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
ClassGUID = "{GUID}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000
DeviceDesc = "{malware filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000\Control
*NewlyCreated* = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000\Control
ActiveService = "{malware filename}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{random filename}
DisplayName = "{malware filename}.exe"

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

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 filename}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{malware filename}\
0000\Control

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_{random filename}\
0000\Control

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

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

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

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:

• Agnitum Ltd
• ALWIL Software
• Anti-Virus
• antimalware
• Avira GmbH
• Beijing Jiangmin
• Beijing Rising
• BITDEFENDER LLC
• BitDefender SRL
• BullGuard Ltd
• Check Point Software Technologies Ltd
• CJSC Returnil Software
• 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
• Kaspersky Lab
• KProcessHacker
• NovaShield Inc
• Panda Software International
• PC Tools
• Quick Heal Technologies
• Sophos Plc
• SUNBELT SOFTWARE
• VirusBuster Ltd

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

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

It does not exploit any vulnerability.