PE_BOBAX.AL
Virus:Win32/Bobax.A (Microsoft); W32/Bobax.worm.gen (McAfee); W32.Bobax!dr (Symantec); Backdoor.Win32.Donbot.p (Kaspersky); BehavesLike.Win32.Malware.bsf (vs) (Sunbelt); Worm/Bobax.X (AVG)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: File infector
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This file infector 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
98,304 bytes
EXE
Yes
14 Jul 2013
Arrival Details
This file infector 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 file infector drops the following copies of itself into the affected system:
- %System%\winldra.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This file infector adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
load32 = "%System%\winldra.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
qugagVPkqifz = "%System%\zcarznw.exe"
Other System Modifications
This file infector deletes the following files:
- %User Temp%\~1.tmp
- %User Temp%\~1.tmp.exe
- %User Temp%\~4.tmp
- %User Temp%\~DF10.tmp
- %User Temp%\~DF7.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\SARS
It adds the following registry entries:
HKEY_CURRENT_USER\Software\SARS
SocksPort = "3da5"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
AllowWindowReuse = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DoNotAllowExceptions = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess
Start = "3"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run\
0B9ECE81
Dropping Routine
This file infector drops the following files:
- %Windows%\netdx.dat
- %Windows%\dvpd.dll
- %Temp%\fe43e701.htm
(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
Other Details
This file infector connects to the following possibly malicious URL:
- http://{BLOCKED}xhosting.com/net/logger.php?{random characters}
- http://{BLOCKED}xhosting.com/net/socks/bot/cmd.txt
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Restart in Safe Mode
Step 3
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.
- In HKEY_CURRENT_USER\Software
- SARS
Step 4
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\Windows\CurrentVersion\Run
- load32 = "%System%\winldra.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- qugagVPkqifz = "%System%\zcarznw.exe"
- In HKEY_CURRENT_USER\Software\SARS
- SocksPort = "3da5"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- AllowWindowReuse = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- DoNotAllowExceptions = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DoNotAllowExceptions = "0"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess
- From: Start = "3"
To: Start = ""2""
- From: Start = "3"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- UpdatesDisableNotify = "1"
Step 6
Search and delete these components
- %Windows%\netdx.dat
- %Windows%\dvpd.dll
- %Temp%\fe43e701.htm
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_BOBAX.AL. 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.
Step 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\~1.tmp
- %User Temp%\~1.tmp.exe
- %User Temp%\~4.tmp
- %User Temp%\~DF10.tmp
- %User Temp%\~DF7.tmp
Step 9
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- 0B9ECE81
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