Prolin is an e-mail worm that spreads itself using MS Outlook. The worm itself is a Windows EXE file about 37Kb long written in VisualBasic. The worm uses the standard "Melissa"-like way of spreading itself: it opens MS Outlook's address book, gets e-mail addresses from there and sends its copies to these addresses.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
The infected messages look like that:
Subject: A great Shockwave flash movie Body: Check out this new flash movie that I downloaded just now ... It's Great Bye Attachment: CREATIVE.EXE
The worm then sends a notification message to his author and informs him about another infected computer:
To:firstname.lastname@example.org Subject: Job complete Message text: Got yet another idiot
Then the worm installs itself to system. It installs itself 2 times on an infected computer. One worm's copy is dropped to root C:\ folder, another one is created in Windows \Start Menu\ folder:
C:\creative.exe C:\WINDOWS\Start Menu\Programs\StartUp\creative.exe
The second copy is specially placed in auto-run directory, so it will be activated during every Windows session.
The worm has a dangerous payload. It scans all available disk drives, gets ZIP, MP3, and JPG files and renames them to C: drive with the name:
C:\%victimfile%change atleast now to LINUX
For example, BGAMEX.jpg and DATA.ZIP are moved to:
C:\BGAMEX.jpgchange atleast now to LINUX C:\DATA.ZIPchange atleast now to LINUX
The worm also creates a text file "messageforu.txt" in root C:\ folder writes some text to there and adds a list of renamed files to the end:
Hi, guess you have got the message. I have kept a list of files that I have infected under this. If you are smart enough just reverse back the process. i could have done far better damage, i could have even completely wiped your harddisk. Remember this is a warning & get it sound and clear... - The Penguin C:\WINDOWS\SYSTEM\OOBE\IMAGEX\BGAMEX.jpg C:\BACKUP\DATA.ZIP
Using this list renamed files can be restored back to their origianal locations if the infected computer has not been rebooted. Otherwise the worm removes the list of the moved files from "messageforu.txt" file.
Technical Details: Kaspersky Labs, F-Secure Corporation; December 2000