O97M.Hopper.V is a stealth macro virus that infects both Microsoft Word documents and Microsoft Excel workbooks. Depending on the day of the month, O97M.Hopper.V may modify data or settings in the Word document or in the Excel workbook.
Modifies files: Data in the active document or the active workbook is modified, deleted or moved.
The process that O97M.Hopper.V uses for Microsoft Word documents and for Microsoft Excel workbooks is described separately.
Microsoft Excel
On deactivation of an infected workbook, the file Book1 is inserted in the \XLStart folder. Then the virus infects Word's Normal.dot template so that the virus will be spread to Word documents.
The Excel payload is dependent upon the day of the month.
If the day of the month is 1, then there is a 1 in 10 chance that 10 random cells selected from the first 100 rows and 100 columns will have the comment "Cross.BadSeed v0.41" added to it.
If the day of the month is 10, then there is a 1 in 3 chance that 150 cell pairs are exchanged. These cells are selected from Column 2 to Column 16 and Row 10 to Row 209.
If the day of the month is 15, then the author name is set to "1nternal"
If the day of the month is 20, then there is a 1 in 5 chance that the status bar displays "Cross.BadSeed v0.41 /1nternal"
Microsoft Word
Whey you close an infected document, the virus stealths by deactivating the following options: Save Normal Prompt, Confirm Conversions, and Virus Protection. The virus then checks to see if the Normal.dot template is already infected. If it is not, then it is infected by copying the viral code from the active document to the Normal.dot template.
Next, the Microsoft Excel \XLStart folder is checked for the presence of the (infected) workbook, Book 1. If this file does not exist, the virus protection option in Excel is deactivated by manipulating the corresponding registry entry, and the Book1 file is inserted in the \XLStart folder, and it is then infected.
After Normal.dot is checked, the active document is inspected. If it is not infected, the virus copies its code from Normal.dot to the active document.
The Word payload, like the Excel payload, is dependent upon the day of the month.
If the day of the month is 1, then there is a 1 in 10 chance that all instances of the character "I" (upper case 'i') in the active document will be changed to "1."
If the day of the month is 5, then there is a 1 in 10 chance that all instances of the word "not" in the active document will be deleted.
If the day of the month is 10, then there is a 1 in 15 chance that the Office Assistant will activate with a text balloon.
The balloon heading reads: "Cross.BadSeed v0.41"
The balloon text reads: "Programmer: 1nternal" "Class Infection: VicodenES" "ActiveX Concept: 1nternal" "Book1. Concept: VicodenES" "" "1nternal also wishes to thank all contributors and supporters which have made Cross.BadSeed possible."
If the day of the month is 20, then there is a 1 in 5 chance that the status bar displays "Cross.BadSeed v0.41 /1nternal."
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.
To recover from this infection:
Run LiveUpdate to make sure that you have the most recent virus definitions.
Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
If any files are detected as infected by O97M.Hopper.V, click Repair.
