WORM_RIMECUD.SMG
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
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.
TECHNICAL DETAILS
Varies
EXE
Yes
03 Aug 2011
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:
- %System Root%\RECYCLER\S-1-5-21-1027092746-4151678385-811904757-8524\MsMxEng.exe
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It drops the following file(s)/component(s):
- %System Root%\RECYCLER\S-1-5-21-1027092746-4151678385-811904757-8524\Desktop.ini
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It creates the following folders:
- %System Root%\RECYCLER\S-1-5-21-1027092746-4151678385-811904757-8524
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
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 = "%System Root%\RECYCLER\S-1-5-21-1027092746-4151678385-811904757-8524\MsMxEng.exe"
Propagation
This worm creates the following folders in all removable drives:
- USBSEC
It drops the following copy(ies) of itself in all removable drives:
- USBSEC\gtk.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:
{garbage}
[autorun
;{garbage}
open=USBSEC/gtk.exe
;{garbage}
icon=%SystemRoot%\system32\SHELL32.dll,4
;{garbage}
action=Open folder to view files using Windows Explorer
;{garbage}
shell\open\\command=USBSEC/gtk.exe
;{garbage}
shell\\explore\command=USBSEC/gtk.exe
;{garbage}
useautoplay=1
;{garbage}