TROJ_BAYROB.VUS
W32/Bayrob.BS!tr (Fortinet), W32/Nivdort.K.gen!Eldorado (FProt), Trojan.Win32.Bayrob (Ikarus), HEUR:Trojan.Win32.Bayrob.gen (Kaspersky), TrojanSpy:Win32/Nivdort (Microsoft), a variant of Win32/Bayrob.BR trojan (NOD32), TrojanSpy.Nivdort.DR3 (Quickheal)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
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.
Installation
This Trojan drops the following files:
- %System Root%\ervmnajxb\ddiric
- %System Root%\ervmnajxb\i1qasu
- %System Root%\ervmnajxb\iwuktty1smy
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It drops the following copies of itself into the affected system:
- %System Root%\ervmnajxb\ag1xqz1x3zzlulm6tbzin.exe
- %System Root%\ervmnajxb\lngtclnx.exe
- %System Root%\ervmnajxb\zksrpfa.exe
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It creates the following folders:
- %System Root%\ervmnajxb
- %Windows%\ervmnajxb
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
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\Human Instrumentation Port Modules
Type = 00000110
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Human Instrumentation Port Modules
Start = 00000002
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Human Instrumentation Port Modules
ErrorControl = 00000000
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Human Instrumentation Port Modules
ImagePath = %System Root%\ervmnajxb\lngtclnx.exe
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Human Instrumentation Port Modules
DisplayName = "Human Instrumentation Port Modules"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Human Instrumentation Port Modules
ObjectName = "LocalSystem"
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
Human Instrumentation Port Modules =
Other System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
FirewallDisableNotify = 00000001
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center\Svc
AntiVirusDisableNotify = 00000001
Other Details
This Trojan connects to the following possibly malicious URL:
- http://agains{BLOCKED}olics.com/index.php
- http://chisty{BLOCKED}tsmen.ru/index.php
- http://cleans{BLOCKED}men.com/index.php
- http://kamcha{BLOCKED}ajivayapriroda.ru/index.php
- http://navsto{BLOCKED}index.php
- http://rps-sv{BLOCKED}n.com/services/countrylookup
- http://solita{BLOCKED}ks.com/index.php
- http://topaut{BLOCKED}s.ru/index.php
NOTES:
It creates registry to disable Security Center functions.
SOLUTION
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
Step 4
Search and delete these folders
- %System Root%\ervmnajxb
- %Windows%\ervmnajxb
Step 5
Delete this registry key
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services
- Human Instrumentation Port Modules
- Human Instrumentation Port Modules
Step 6
Delete this registry value
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\Microsoft\Security Center\Svc
- FirewallDisableNotify = 00000001
- FirewallDisableNotify = 00000001
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\Svc
- AntiVirusDisableNotify = 00000001
- AntiVirusDisableNotify = 00000001
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BAYROB.VUS. 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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