Stoned.Angelina

SUMMARY

Stoned.Angelina is a boot virus that infects the DOS boot sector of floppy disks and the master boot record (MBR) of hard disks.

Protection

• Virus Definitions (Intelligent Updater) January 5, 1994

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

The boot virus code is one sector in length with the infectious code being stored at side 0, track 0, sector 1 and the original master boot record code being stored at side 0, track 0 sector 2. On floppy disks, Stoned.Angelina calculates the last sector of the root directory and uses this location to store a copy of the original DOS boot sector.

In addition to standard viral replication, Stoned.Angelina contains a block of code designed to stealth (by means of redirection) any reads to the physical location side 0, track 0 sector 1 on both floppy disks and hard disks.

Contained within the virus code body is the following encrypted text, which is never displayed on the screen:

Greetings for ANGELINA!!!/by Garfield/Zielona Gora

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

You must use the fdisk /mbr command to repair an infected MBR. Please read all instructions before you begin.

CAUTION:

• The procedure described in this document could result in the loss of all data on the computer if not done correctly. Unless you are completely familiar with the use of the DOS FDISK command, we suggest that you obtain the services of a qualified computer consultant.
• If your computer uses a Dynamic Drive Overlay, or if you are not sure, first follow the instructions in the document How to repair a virus when using a dynamic drive overlay or a disk compression utility.
  

To remove the virus:

1. Shut down Windows, and then turn off the power. Do not simply press the reset button.
2. Wait 30 seconds for memory to be cleared.
3. Do one of the following:
   • If you have a NAV 2001 (or later) CD and your computer can boot from the CD-ROM drive:
     1. Insert the NAV CD into the CD-ROM drive.
     2. Restart the computer, and follow the prompts.
     3. Choose to repair all infections.
     4. Remove the floppy disk, and then restart the computer.
     5. Start Norton AntiVirus, and run a full system scan.
   • If you have a current Rescue Disk set or you can create one on an uninfected computer:
     1. Insert the first, write-protected disk of the Rescue Disk set into the floppy disk drive.
     2. Restart the computer, and follow the prompts.
     3. Choose to repair all infections.
     4. Remove the floppy disk, and then restart the computer.
     5. Start Norton AntiVirus, and run a full system scan.
   • If you do not have a clean Rescue disk or a NAV 2001 (or later) CD:
     1. Insert an uninfected, write-protected, bootable disk that also contains the FDISK program into the floppy disk drive, and then restart the computer.
     2. Type the following, and then press Enter:
        
        fdisk /mbr
        
     3. Remove the floppy disk, and then restart the computer.
     4. Start Norton AntiVirus, and run a full system scan.