Worm.Win32.PALEVO.AL
P2P-Worm.Win32.Palevo (IKARUS)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted: No
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.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
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%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe → with READONLY, HIDDEN, and SYSTEM attributes
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It drops the following files:
- %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini → with HIDDEN, and SYSTEM attributes
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini → with HIDDEN, and SYSTEM attributes
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\autorun.inf → with READONLY, HIDDEN, and SYSTEM attributes
(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%\RECYCLER → with READONLY, HIDDEN, and SYSTEM attributes
- %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013 → with READONLY, HIDDEN, and SYSTEM attributes
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- asd-6+094997_
It injects threads into the following normal process(es):
- explorer.exe
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
Internet Security Service = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe → if HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}\StubPath does not exist
HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
StubPath = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
Other System Modifications
This Worm adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components
{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612} =
Propagation
This Worm creates the following folders in all removable drives:
- {Removable Drive Letter}:\RECYCLER → with READONLY, HIDDEN, and SYSTEM attributes
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013 → with READONLY, HIDDEN, and SYSTEM attributes
It drops the following copy(ies) of itself in all removable drives:
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe → with READONLY, HIDDEN, and SYSTEM attributes
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[autorun]
open=RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
shell\open\default=1
Backdoor Routine
This Worm executes the following commands from a remote malicious user:
- Flooding (DDOS)
- Execute arbitrary commands from remote user
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- tcp://{BLOCKED}adool400.com:6666
However, as of this writing, the said sites are inaccessible.
Rootkit Capabilities
This Worm does not have rootkit capabilities.
NOTES:
This Worm does not exploit any vulnerability.
SOLUTION
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- Troj.Win32.TRX.XXPE50FFF076
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
Restart in Safe Mode
Step 5
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\Active Setup\Installed Components\{28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
- StubPath = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- StubPath = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Internet Security Service = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- Internet Security Service = %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
Step 6
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\Software\Microsoft\Active Setup\Installed Components
- {28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
- {28ABC5C0-4FCB-11CF-AAX5-81CX1C635612}
Step 7
Search and delete AUTORUN.INF files created by Worm.Win32.PALEVO.AL that contain these strings
- [autorun]
- open=RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- icon=%SystemRoot%\system32\SHELL32.dll,4
- action=Open folder to view files
- shell\open=Open
- shell\open\command=RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- shell\open\default=1
Step 8
Search and delete these files
- %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini
- %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\Desktop.ini
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013\ise32.exe
Step 9
Search and delete these folders
- %System Root%\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013
- %System Root%\RECYCLER
- {Removable Drive Letter}:\RECYCLER\S-1-5-21-1482476501-1644491937-682003330-1013
- {Removable Drive Letter}:\RECYCLER
Step 10
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.Win32.PALEVO.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.
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