Backdoor.Win32.ZEGOST.AB
HEUR:Trojan.Win32.Generic (Kaspersky) ; a variant of Win32/Packed.NoobyProtect.O suspicious application (ESET-Nod32)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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 steals certain information from the system and/or the user.
TECHNICAL DETAILS
1,389,568 bytes
EXE, DLL
No
02 Apr 2019
Connects to URLs/IPs, Steals information
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.
Installation
This Backdoor drops the following copies of itself into the affected system:
- %System%\AppleOSSMgr.exe
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It drops the following files:
- {Malware Directory}\$$a39494$$.bat -> deletes the original copies of itself
- %System%\AppleOSSMgr.dll -> Detected also as Backdoor.Win32.ZEGOST.AB
- %System%\AppleOSSMgr.dat -> Component file
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Autostart Technique
This Backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\ControlSet001\services\
AppleOSSMgr
Description = Provides support for switching between OS X and Windows
HKEY_LOCAL_MACHINE\ControlSet001\services\
AppleOSSMgr\Parameters
ServiceDll = %System%\AppleOSSMgr.dll
HKEY_LOCAL_MACHINE\ControlSet001\services\
AppleOSSMgr
ImagePath = %System%\svchost.exe -k netsvcs
HKEY_LOCAL_MACHINE\Microsoft\Windows NT\
CurrentVersion\Svchost
netsvcs = {Original Value}, AppleOSSMgr
Other System Modifications
This Backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
WinOldApp
Backdoor Routine
This Backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}.{BLOCKED}.242.151:2014
Information Theft
This Backdoor steals the following information:
- OS Information
- Workstation Type
Other Details
This Backdoor does the following:
- This backdoor has the following capabilities:
- Modify Registry Entries
- Enumerate Drives
- Get Clipboard Contents
- Remote Desktop
- Screen Capture
- Download Files
- Upload Files
- Video Capture
- Remote command execution
- Send and Receive Audio
- Send and Receive Text via Chatbox
SOLUTION
9.850
14.939.00
14 Apr 2019
14.939.00
14 Apr 2019
Step 1
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 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, and then 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_LOCAL_MACHINE\SYSTEM\ControlSet001\Services
- AppleOSSMgr
- AppleOSSMgr
Step 4
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\Microsoft\Windows\CurrentVersion\Policies
- WinOldApp
- WinOldApp
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.ZEGOST.AB. 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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