Classification

Category: Malware

Type: Worm

Aliases: Updater, I-Worm.Updater

Summary


Updater is a mass mailing worm that is a Windows PE executable. Its size is about 12 KB and it is written in Visual Basic (VB6). It packed by the program UPX. After unpacking its size is 45 KB.

The worm activates from infected email only in case a user clicks on attached file. The worm then installs itself to the system, runs spreading routine and payload.

Removal


Automatic action

Based on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the detected program or file, or ask you for a desired action.

Knowledge Base

Find the latest advice in our Community Knowledge Base.

About the product

See the manual for your F-Secure product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details


The infected messages have different texts and attached file names, they are randomly selected by worm while spreading from following variants:

Subjects are:

 Part1 + Part2 + Part3 + Part4

 Part1 = "Have you ", "You Should ", "Just ", "Why Not you ", "How to ", "Re: ",

 "Fwd : ", " "
 Part2 = "Check ", "Check out ", "Watch out ", "Open ", "Look at "
 Part3 = "this ", "my ", "For this ", "The "
 Part4 = "Picture", "Program", "Patch", "Nude pic", "Report", "Documment",

 "Quotation", "Transaction", "Bank Account", "WTC Tragedy", "Osama Vs Bush"

 "Account", "Private Pic" 		
 

Examples:

You Should Look at this Osama Vs Bush
 Fwd : Check my Patch

Atach filenames are:

"Setup.EXE", "install.exe", "Readme.exe", "Files.exe", "Picture.exe"
 "Quotation.Doc.exe", "Letter.Doc.exe", "Picture.jpg.exe"
 

Body:

Hi:
This is the file you ask for, Please save it to disk and open this file,
it's very important.
 

When the worm is executed, it copies itself to the C:\WINDOWS\ directory with the UPDATE.EXE name and registers that file in system registry auto-run key:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run

 Update = C:\WINDOWS\Update.exe 	

The worm then displays a fake error message:

Cannot Open files : It does not appear to be a valid archive
if you Downloaded this file , try downloading the file again.
 [ OK ]

Next the worm creates the file C:\WINDOWS\STARTM~1\PROGRAMS\STARTUP\Update.vbs. This script file starts automatically after rebooting system under Windows 9x/ME. It looks for files on all drives with expansions: EXE, DOC, TXT. It creates script copies with the same names + expantion: ".vbs" For example:

MPLAYER.EXE.vbs
 NOTEPAD.EXE.vbs

This script file contains the strings:

I-WORM.IMELDA.B

The worm changes a volume label on disk C: the the IMELDA.

The worm also copies itself to the C:\WINDOWS\ directory with one of this names:

"Setup.EXE", "install.exe", "Readme.exe", "Files.exe",
"Picture.exe" "Quotation.Doc.exe", "Letter.Doc.exe", "Picture.jpg.exe"