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Backdoor.Win32.NOVTER.A

October 03, 2019
 Analysis by: Jemimah Mae Molina
 ALIASES:

Trojan:Win32/Kovter.I (Microsoft); RDN/Generic.grp (McAfee); Trojan.Win32.Agentb.bxmd (Kaspersky); Mal/EncPk-ACO (Sophos); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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. It may be downloaded by other malware/grayware from remote sites.

It steals certain information from the system and/or the user.

  TECHNICAL DETAILS

File Size:

84,992 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

29 Sep 2019

Payload:

Connects to URLs/IPs

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.

It may be downloaded by the following malware/grayware from remote sites:

Installation

This Backdoor adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\CreatorsPatch

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{10 random characters} = %ProgramData%\{10 random characters}.hta

Other System Modifications

This Backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}
{10 random characters} = {hex data}

HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}
{10 random characters} = {javascript code}

HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}
{10 random characters} = {powershell code}

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows Defender\
Real-Time Protection
DisableRealtimeMonitoring = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows Defender
DisableAntiSpyware = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows Defender
DisableRoutinelyTakingAction = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender\Real-Time Protection
DisableRealtimeMonitoring = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender
DisableAntiSpyware = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender
DisableRoutinelyTakingAction = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows\
WindowsUpdate\AU
NoAutoUpdate = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows\
WindowsUpdate\AU
AUOptions = 2

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows\
WindowsUpdate\AU
ScheduledInstallDay = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Policies\Microsoft\Windows\
WindowsUpdate\AU
ScheduledInstallTime = 3

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
NoAutoUpdate = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
AUOptions = 2

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
ScheduledInstallDay = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate\
AU
ScheduledInstallTime = 3

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\DeliveryOptimization
DODownloadMode = 0

Backdoor Routine

This Backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}.{BLOCKED}.114.111/
  • {BLOCKED}.{BLOCKED}.42.103:443
  • {BLOCKED}.{BLOCKED}.221.156:443
  • {BLOCKED}.{BLOCKED}.8.85:443
  • {BLOCKED}.{BLOCKED}.10.66:443
  • {BLOCKED}.{BLOCKED}.178:80/
  • {BLOCKED}.{BLOCKED}172.4:80/
  • {BLOCKED}.{BLOCKED}.123.173:80/
  • {BLOCKED}.{BLOCKED}.38.32:80/
  • {BLOCKED}.{BLOCKED}66.73:80/
  • {BLOCKED}.{BLOCKED}.211.3:80/
  • {BLOCKED}.{BLOCKED}.188.148:80/
  • {BLOCKED}.{BLOCKED}.192.87:80/
  • {BLOCKED}.{BLOCKED}154.177:80/
  • {BLOCKED}.{BLOCKED}.35.108:80/
  • {BLOCKED}.{BLOCKED}.82.121:80/
  • {BLOCKED}.{BLOCKED}.62.98:80/
  • {BLOCKED}.{BLOCKED}115.133:80/
  • {BLOCKED}.{BLOCKED}.31.99:80/
  • {BLOCKED}.{BLOCKED}.207.62:80/
  • {BLOCKED}.{BLOCKED}.55.96:80/
  • {BLOCKED}.{BLOCKED}.178.246:80/
  • {BLOCKED}.{BLOCKED}.122.149:80/
  • {BLOCKED}.{BLOCKED}189.110:80/
  • {BLOCKED}.{BLOCKED}.45.155:80/
  • {BLOCKED}.{BLOCKED}.255.171:80/
  • {BLOCKED}.{BLOCKED}.255.171:80/
  • {BLOCKED}.{BLOCKED}.255.171:80/
  • {BLOCKED}.{BLOCKED}.255.171:80/
  • {BLOCKED}.{BLOCKED}.208.54:80/
  • {BLOCKED}.{BLOCKED}149.42:80/
  • {BLOCKED}.{BLOCKED}244.209:80/
  • {BLOCKED}.{BLOCKED}.45.182:80/
  • {BLOCKED}.{BLOCKED}.4.54:80/
  • {BLOCKED}.{BLOCKED}4.248.219:80/
  • {BLOCKED}.{BLOCKED}.154.139:80/
  • {BLOCKED}.{BLOCKED}.166.154:80/
  • {BLOCKED}.{BLOCKED}6.99.237:80/
  • {BLOCKED}.{BLOCKED}1.228.56:80/
  • {BLOCKED}.{BLOCKED}9.127.9:80/
  • {BLOCKED}.{BLOCKED}6.67.4:80/
  • {BLOCKED}.{BLOCKED}1.161.154:80/
  • {BLOCKED}.{BLOCKED}.159.251:80/
  • {BLOCKED}.{BLOCKED}0.206.114:80/
  • {BLOCKED}.{BLOCKED}.82.109:80/
  • {BLOCKED}.{BLOCKED}.7.197:80/
  • {BLOCKED}.{BLOCKED}.27.82:80/
  • {BLOCKED}.{BLOCKED}2.198.216:80/
  • {BLOCKED}.{BLOCKED}8.238.238:80/
  • {BLOCKED}.{BLOCKED}8.238.238:80/
  • {BLOCKED}.{BLOCKED}72.59:80/
  • {BLOCKED}.{BLOCKED}.20.141:80/
  • {BLOCKED}.{BLOCKED}9.208.24:80/
  • {BLOCKED}.{BLOCKED}9.211.36:80/
  • {BLOCKED}.{BLOCKED}6.74.143:80/
  • {BLOCKED}.{BLOCKED}8.171.30:80/
  • {BLOCKED}.{BLOCKED}.249.44:80/
  • {BLOCKED}.{BLOCKED}.10.105:80/
  • {BLOCKED}.{BLOCKED}8.221.45:80/
  • {BLOCKED}.{BLOCKED}5.27.234:80/
  • {BLOCKED}.{BLOCKED}4.96.116:80/
  • {BLOCKED}.{BLOCKED}.117.82:80/
  • {BLOCKED}.{BLOCKED}.128.55:80/
  • {BLOCKED}.{BLOCKED}.117.200:80/
  • {BLOCKED}.{BLOCKED}.117.200:80/
  • {BLOCKED}.{BLOCKED}.242.151:80/
  • {BLOCKED}.{BLOCKED}.240.5:80/
  • {BLOCKED}.{BLOCKED}1.26.176:80/
  • {BLOCKED}.{BLOCKED}.197.25:80/
  • {BLOCKED}.{BLOCKED}9.174.17:80/
  • {BLOCKED}.{BLOCKED}9.34.21:80/
  • {BLOCKED}.{BLOCKED}0.223.93:80/
  • {BLOCKED}.{BLOCKED}8.224.121:443/
  • {BLOCKED}.{BLOCKED}.38.248:443/
  • {BLOCKED}.{BLOCKED}7.65.82:443/
  • {BLOCKED}.{BLOCKED}7.141.103:443/
  • {BLOCKED}.{BLOCKED}5.123.173:443/
  • {BLOCKED}.{BLOCKED}.32.1:443/
  • {BLOCKED}.{BLOCKED}.196.120:443/
  • {BLOCKED}.{BLOCKED}0.192.98:443/
  • {BLOCKED}.{BLOCKED}.99.198:443/
  • {BLOCKED}.{BLOCKED}9.44.27:443/
  • {BLOCKED}.{BLOCKED}.202.39:443/
  • {BLOCKED}.{BLOCKED}7.211.62:443/
  • {BLOCKED}.{BLOCKED}.30.31:443/
  • {BLOCKED}.{BLOCKED}1.249.41:443/
  • {BLOCKED}.{BLOCKED}.205.106:443/
  • {BLOCKED}.{BLOCKED}4.8.97:443/
  • {BLOCKED}.{BLOCKED}6.178.248:443/
  • {BLOCKED}.{BLOCKED}.179.174:443/
  • {BLOCKED}.{BLOCKED}3.58.172:443/
  • {BLOCKED}.{BLOCKED}8.26.25:443/
  • {BLOCKED}.{BLOCKED}3.255.171:443/
  • {BLOCKED}.{BLOCKED}3.255.171:443/
  • {BLOCKED}.{BLOCKED}3.255.171:443/
  • {BLOCKED}.{BLOCKED}3.255.171:443/
  • {BLOCKED}.{BLOCKED}3.255.171:443/
  • {BLOCKED}.{BLOCKED}6.235.93:443/
  • {BLOCKED}.{BLOCKED}1.4.11:443/
  • {BLOCKED}.{BLOCKED}24.248.219:443/
  • {BLOCKED}.{BLOCKED}93.149.210:443/
  • {BLOCKED}.{BLOCKED}00.116.116:443/
  • {BLOCKED}.{BLOCKED}8.2.169:443/
  • {BLOCKED}.{BLOCKED}03.174.8:443/
  • {BLOCKED}.{BLOCKED}06.30.104:443/
  • {BLOCKED}.{BLOCKED}39.101.62:443/
  • {BLOCKED}.{BLOCKED}15.147.176:443/
  • {BLOCKED}.{BLOCKED}7.136.53:443/
  • {BLOCKED}.{BLOCKED}44.233.215:443/
  • {BLOCKED}.{BLOCKED}8.87.235:443/
  • {BLOCKED}.{BLOCKED}0.39.164:443/
  • {BLOCKED}.{BLOCKED}0.128.87:443/
  • {BLOCKED}.{BLOCKED}3.159.95:443/
  • {BLOCKED}.{BLOCKED}5.113.89:443/
  • {BLOCKED}.{BLOCKED}.72.36:443/
  • {BLOCKED}.{BLOCKED}.225.31:443/
  • {BLOCKED}.{BLOCKED}11.192.173:443/
  • {BLOCKED}.{BLOCKED}2.66.116:443/
  • {BLOCKED}.{BLOCKED}0.118.219:443/
  • {BLOCKED}.{BLOCKED}59.211.43:443/
  • {BLOCKED}.{BLOCKED}31.22.201:443/
  • {BLOCKED}.{BLOCKED}.24.233:443/
  • {BLOCKED}.{BLOCKED}7.158.168:443/
  • {BLOCKED}.{BLOCKED}0.129.67:443/
  • {BLOCKED}.{BLOCKED}68.221.63:443/
  • {BLOCKED}.{BLOCKED}68.221.42:443/
  • {BLOCKED}.{BLOCKED}68.131.241:443/
  • {BLOCKED}.{BLOCKED}14.96.87:443/
  • {BLOCKED}.{BLOCKED}1.128.74:443/
  • {BLOCKED}.{BLOCKED}55.0.138:443/
  • {BLOCKED}.{BLOCKED}4.115.200:443/
  • {BLOCKED}.{BLOCKED}9.242.150:443/
  • {BLOCKED}.{BLOCKED}60.153.229:443/
  • {BLOCKED}.{BLOCKED}1.56.48:443/
  • {BLOCKED}.{BLOCKED}7.221.148:443/
  • {BLOCKED}.{BLOCKED}30.250.157:443/
  • {BLOCKED}.{BLOCKED}60.231.125:443/
  • {BLOCKED}.{BLOCKED}.79.45:443/

Dropping Routine

This Backdoor drops the following files:

  • %ProgramData%\{10 random characters}.hta

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

Information Theft

This Backdoor steals the following information:

  • Build GUID
  • Original Install Date
  • Digital Product ID
  • Registered Owner
  • UID
  • SubID
  • OS Major Version
  • OS Minor Version
  • OS Build Number
  • OS Product Type
  • User Privilege
  • System Integrity Level
  • Processor Count
  • Total and Available Memory
  • Installed Antivirus Software
  • System Uptime

Other Details

This Backdoor does the following:

  • It executes the following commands from a remote malicious user:
    • killall → terminate all processes and delete their corresponding files
    • kill → terminate a specified process and delete the corresponding file
    • stop → terminate a specified process
    • resume → start a specified process
    • modules → download and execute a specified file
    • update → download and install an update
    • update_interval → set an interval between update attempts
  • It attempts to bypass UAC using CMSTPLUA COM interface.
  • It connects to {BLOCKED}.{BLOCKED}.114.111 to send which anti-analysis check failed to pass then sleeps indefinitely if any of the following conditions are met:
    • If any of the following processes are found in the affected system's memory:
      • ProcessHacker.exe
      • tcpview.exe
      • Autoruns.exe
      • filemon.exe
      • procmon.exe
      • regmon.exe
      • IDAQ.exe
      • ImmunityDebugger.exe
      • wireshark.exe
      • ImportREC.exe
      • sysAnalyzer.exe
      • windbg.exe
      • JoeBoxControl.exe
      • JoeBoxServer.exe
      • vmtoolsd.exe
      • vmsrvc.exe
      • vmusrvc.exe
      • vboxtray.exe
      • vboxservice.exe
      • VMwareTray.exe
    • If any of the following modules are found in the affected system's memory:
      • SbieDll.dll
      • api_log.dll
      • WpeSpy.dll
    • If the number of processors is less than 2.
    • If a debugger is present.
    • If uptime intervals are less than 4000ms.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.402.03

FIRST VSAPI PATTERN DATE:

01 Oct 2019

VSAPI OPR PATTERN File:

15.400.04

VSAPI OPR PATTERN Date:

02 Oct 2019

Step 1

Trend Micro products with the XGen technology detect this malware as

[ Learn More ]
 Troj.Win32.TRX.XXPE50FFF031

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Identify and terminate files detected as Backdoor.Win32.NOVTER.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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\SOFTWARE
    • {10 random characters}

Step 6

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\SOFTWARE\{10 random characters}
    • {10 random characters} = {hex data}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}
    • {10 random characters} = {javascript code}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\{10 random characters}
    • {10 random characters} = {powershell code}

Step 7

Restore this modified 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\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows Defender\Real-Time Protection
    • From: DisableRealtimeMonitoring = 1
      To: DisableRealtimeMonitoring = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows Defender
    • From: DisableAntiSpyware = 1
      To: DisableAntiSpyware = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows Defender
    • From: DisableRoutinelyTakingAction = 1
      To: DisableRoutinelyTakingAction = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection
    • From: DisableRealtimeMonitoring = 1
      To: DisableRealtimeMonitoring = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
    • From: DisableAntiSpyware = 1
      To: DisableAntiSpyware = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
    • From: DisableRoutinelyTakingAction = 1
      To: DisableRoutinelyTakingAction = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: NoAutoUpdate = 0
      To: NoAutoUpdate = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: AUOptions = 2
      To: AUOptions = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: ScheduledInstallDay = 0
      To: ScheduledInstallDay = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: ScheduledInstallTime = 3
      To: ScheduledInstallTime = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: NoAutoUpdate = 0
      To: NoAutoUpdate = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: AUOptions = 2
      To: AUOptions = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: ScheduledInstallDay = 0
      To: ScheduledInstallDay = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
    • From: ScheduledInstallTime = 3
      To: ScheduledInstallTime = {default value}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\DeliveryOptimization
    • From: DODownloadMode = 0
      To: DODownloadMode = {default value}

Step 8

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.
  • %ProgramData%\{10 random characters}.hta

Step 9

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win32.NOVTER.A. 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 the following Trend Micro Support pages for more information:


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