WORM_PALEVO.AND
Trojan:Win32/Rimecud.A (Microsoft), W32/Worm-FDK!B70E7ABCC3FC (McAfee), Troj/Rimecud-DG (Sophos), Trojan.Win32.Rimecud.f (v) (Sunbelt), W32/Palevo.L.gen!Eldorado (F-Prot), Gen:Variant.Symmi.11323 (Bitdefender), W32/Palevo.MATH!worm (Fortinet), Win32/Kryptik.ARFM trojan (ESET), BScope.Worm.Palevo.2213 (VBA32), Virus.Win32.Cryptor (Ikarus)
Windows 2000, Windows XP (32-bit and 64-bit), Windows Server 2003, Windows Vista (32-bit and 64-bit), Windows 7 (32-bit and 64-bit)

Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. It 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.
TECHNICAL DETAILS
Arrival Details
This worm arrives via removable drives.
It 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:
- %User Profile%\{random}.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- 5(*w+10
It injects itself into the following processes as part of its memory residency routine:
- svchost.exe
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%User Profile%\{random}.exe"
Propagation
This worm creates the following folders in all removable drives:
- emetio
It drops the following copy(ies) of itself in all removable drives:
- {Removable Drive}:emetio\pedroka.exe
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]
;garbage characters
shell\open\command=emetio\pedroka.exe
;garbage characters
action=Open folder to view files using Windows Explorer
;garbage characters
Shell\Open\Command=emetio\pedroka.exe
;garbage characters
shellexecute=emetio\pedroka.exe
;garbage characters
shell\explore\command=emetio\pedroka.exe
;garbage characters
icon=SHELL32.dll,4
;garbage characters
open=emetio\pedroka.exe
;garbage characters
USEAUTOPLAY=1
;garbage characters
Backdoor Routine
This worm executes the following commands from a remote malicious user:
- MSN spreader
- P2P Spreader
- DDOS (TCP/UDP Flooding)
- Retrieve Stored Browser Passwords
- Update / Remove self
- Download and execute arbitrary files
- USB Spreader
- Visit a URL / Display pop-up advertisements
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}t.{BLOCKED}s.su
- {BLOCKED}t.{BLOCKED}e.kz
- {BLOCKED}a.{BLOCKED}e.com
- {BLOCKED}a.{BLOCKED}sk.net
- {BLOCKED}a.{BLOCKED}est.com
Information Theft
This worm gathers the following data:
- IP Address
- Network Setting
- Operation System
- Admin Rights
- Country
- Port Used
- Username / Hostname
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
Identify and delete files detected as WORM_PALEVO.AND using either the Startup Disk or Recovery Console
Step 3
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 NT\CurrentVersion\Winlogon
- Taskman = "%User Profile%\{random}"
- Taskman = "%User Profile%\{random}"
Step 4
Search and delete AUTORUN.INF files created by WORM_PALEVO.AND that contain these strings
- [autorun]
- ;garbage characters
- shell\open\command=emetio\pedroka.exe
- ;garbage characters
- action=Open folder to view files using Windows Explorer
- ;garbage characters
- Shell\Open\Command=emetio\pedroka.exe
- ;garbage characters
- shellexecute=emetio\pedroka.exe
- ;garbage characters
- shell\explore\command=emetio\pedroka.exe
- ;garbage characters
- icon=SHELL32.dll,4
- ;garbage characters
- open=emetio\pedroka.exe
- ;garbage characters
- USEAUTOPLAY=1
- ;garbage characters
Step 5
Search and delete these folders
- {Removable Drive}:\emetio
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_PALEVO.AND. 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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