O97M.Toraja.Gen

SUMMARY

O97M.Toraja.Gen is a macro virus, which infects Microsoft Word and Microsoft Excel documents. In Word it infects the Normal.dot template, and in Excel it contaminates the XLStart folder with an infected Excel workbook. Many standard menu functions are overridden, making them inaccessible.

NOTE: O97M.Toraja.Gen is a generic detection for viruses in the O97M.Toraja family. In some cases, Norton AntiVirus detects specific variants such as O97M.Toraja.C. The information in this writeup applies to the specific detections, as well as the generic detection.

Protection

• Virus Definitions (Intelligent Updater) June 6, 2000

Threat Assessment

Wild

• Wild Level: Medium
• Number of Infections: More than 1000
• Number of Sites: More than 10
• Geographical Distribution: High
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload Trigger: Initial infection date + 30 days
• Payload: Displays messages in Status Bar and Caption

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

When you open an infected document or workbook, O97M.Toraja.Gen does the following:

1. It infects the Normal.dot file (Microsoft Word) or inserts a copy of the infected workbook in the XLStart folder with the file name Start12.xls.
2. All recently accessed documents are infected.
3. O97M.Toraja.Gen searches for and deletes all but a few macro components, so that it is highly likely that O97M.Toraja.Gen is the only macro in the infected documents or workbooks. The components that are left alone are:
   • "ThisDocument"
   • "ThisWorkbook"
   • "Reference To Normal"
   • Components that start with "Sheet"
   • Components that start with "Chart"
   • The O97M.Toraja.Gen viral component

When O97M.Toraja.Gen infects a system for the first time, the date is saved and the trigger date is set to a specific number of days (for example 30 days), after the infection date. When the trigger date is reached, messages may appear in the caption and in the status bar. The exact message depends on the exact month on which this is triggered. This can include the following messages:

• Toraja High Land:
• Note ... each file can be printed 5 times only: " (This is followed by a seconds counter.)

After the initial infections, O97M.Toraja.Gen goes stealth by:

• Disabling the VirusProtection option
• Disabling the SaveNormalPrompt option
• Disabling the shortcut key to the Macro menu
• Disabling the shortcut key to the Visual Basic Editor
• Locking and removing some CommandBars

The following actions are overridden by O97M.Toraja.Gen:

• Tools > Macro > Macros
• Tools > Macro > Record New Macro
• Tools > Macro > Visual Basic Editor
• Tools > Customize
• File > Print
• Format > Style

When trying to access any of these items, the desired action is not performed, but instead the window is maximized.

When creating a new document or opening an existing one, the document is immediately infected by O97M.Toraja.Gen.

O97M.Toraja.Gen keeps track of how many times a document is printed. During any one Word/Excel session, O97M.Toraja.Gen allows a document to be printed five times. When over multiple sessions, the total number of prints exceeds a specified number (for example, 250), O97M.Toraja.Gen disallows any more printing. When the virus disallows printing, it still shows the Print menu, but any printing actions from there on are ignored.

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

To remove this virus:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
3. If any files are detected as infected by O97M.Toraja.Gen, click Repair.