Worm.MSIL.WOONIKY.AA
GenericRXHE-ML!C9CFCFCDD02A (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Agentb.aaew (Kaspersky); Mal/MSIL-HT, Mal/MSIL-HT, Mal/MSIL-HT (Sophos); Trojan.Win32.Generic!BT (Sunbelt)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Worm 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
189,440 bytes
EXE
Yes
05 Nov 2019
Arrival Details
This Worm 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 Worm drops the following copies of itself into the affected system:
- %System Root%\ProgramFileas\windowsdeafender.exe
- F:\Yeni Klasorr.exe
- F:\data.exe
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It adds the following processes:
- %System Root%\ProgramFileas\winlogoon.exe
- attrib +h +r +s %System Root%\ProgramFileas
- %Windows%\explorer.exe \0de9bd260302f0f154769796fe580296c56ac401
- attrib +h +r +s F:\data
- %System Root%\ProgramFileas\svchoost.exe
(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.)
It creates the following folders:
- %System Root%\ProgramFileas\data
- %System Root%\ProgramFileas
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
Autostart Technique
This Worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
winlogoon = "%System Root%\ProgramFileas\winlogoon.exe"
Dropping Routine
This Worm drops the following files:
- %System Root%\ProgramFileas\data\tmp.doc
- %System Root%\ProgramFileas\svchoost.exe
- %System Root%\ProgramFileas\winlogoon.exe
- %AppDataLocal%\GDIPFONTCACHEV1.DAT
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
This report is generated via an automated analysis system.
SOLUTION
9.850
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
Restart in Safe Mode
Step 3
Identify and terminate files detected as Worm.MSIL.WOONIKY.AA
- 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.
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- winlogoon = "%System Root%\ProgramFileas\winlogoon.exe"
Step 5
Search and delete these components
- %System Root%\ProgramFileas\data\tmp.doc
- %System Root%\ProgramFileas\svchoost.exe
- %System Root%\ProgramFileas\winlogoon.exe
- %AppDataLocal%\GDIPFONTCACHEV1.DAT
Step 6
Search and delete these folders
- %System Root%\ProgramFileas\data
- %System Root%\ProgramFileas
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.MSIL.WOONIKY.AA. 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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