Virus Database

Cannabis

Description Cannabis

It's a not dangerous memory resident floppy boot-sectors infector. It hooks INT 13h. It contains the word "Cannabis". It also types:
Hey man, I don't wanna work. I'm too stoned right nowall
Non-System disk or disk error
Replace and press a key when ready

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Macro.Word97.MDMA

Description Macro.Word97.MDMA

This virus contains only one macro: AutoClose. It infects the system on closing an infected file, it writes itself to documents that are also closed. Under Macintosh after 4th of any month the virus wipes out the files on disk.

Macro.Word97.Melissa

Description Macro.Word97.Melissa

This macro-virus replicates under Word 8 and Word 9 (Office97 and Office2000), infects Word document and templates, and sends its copies via e-mail messages using MS Outlook. The virus is an extremely fast infector: its e-mail spreading routine may send many infected documents to different e-mail addresses when the virus installs itself into the system. The virus also has a trigger routine, changes the system registry, and disables the Word macro-virus protection.
To send its copies via e-mail messages, the virus uses VisualBasic abilities to activate other Microsoft applications and use their routines: the virus gains access to MS Outlook and summons its functions. The virus obtains the addresses from the Outlook database and sends them a new message. This massage has:
The subject: "Important Message From [UserName]" (UserName is variable)

Message body: "Here is that document you asked for all don't show anyone else ;-)"
The message also has an attached document (needless to say that it is infected) - the virus attaches to the document that is being edited now (active document). As a side effect of this way of spreading, the user's documents (including confidential ones) can be sent out on the Internet.
The virus can send very many messages: it scans Outlook AddressBook (address database), opens each list in it, and sends up to 50 messages to addresses from each one. If a list has less than 50 entries (e-mail addresses), all of them are affected. The virus sends one message per each list, the TO: field in the message contains all the addresses from this list (up to 50), and can be disregarded by anti-spam filters.
The virus sends infected e-mail only one at a time. Before sending, the virus checks system registry for its ID stamp:
HKEY_CURRENT_USERSoftwareMicrosoftOffice "Melissa?" = "... by Kwyjibo"
If this entry does not exist, the virus sends e-mail from an infected computer, and then creates this entry in the registry. Otherwise, the virus skips the e-mail routine. As a result, the virus sends infected e-mail messages only once: during subsequent attempts, it locates the "Melissa?=" entry, and skips it.
The virus is able to spread to Office2000 (Word ver.9) documents. This possibility is based on an Office "converting" feature. When new a Office version opens and loads documents and templates created by previous Word versions, it converts data in documents to new formats. The macro-program in files are also converted, including virus macros. As a result, the virus is able to replicate itself under Office2000.
In the case that the virus is run in Office2000, it performs an additional action: it disables (sets to a minimal level) Office2000 security settings (anti-virus protection).
The virus code contains one module named "Melissa" with one auto-function in it: "Document_Open" in infected documents, or "Document_Closed" in NORMAL.DOT (global macros area). The virus infects the global macros area on an infected document opening, and spreads to other documents upon their closing. To infect documents and templates, the virus copies its code line-by-line from an infected object to a "victim" one. In the case that the NORMAL.DOT is being infected, the virus names its program in the module as "Document_Close", when the virus copies its code from NORMAL.DOT to a document, the virus names it "Document_Open". As a result, the virus installs itself into the Word application at the same time the infected document is open, and infects other documents only when they are closed.
The virus also has a trigger routine that is activated if the current date is equal to the current time in minutes. Each time the virus' macros gain control, this routine inserts the text into the current document:
Twenty-two points, plus triple-word-score, plus fifty points for using
all my letters. Game's over. I'm outta here.
This text, as well as the pseudonym of the virus author, "Kwyjibo", are references to the popular "Simpsons" cartoon TV series.
The virus has the comments:
WORD/Melissa written by Kwyjibo
Works in both Word 2000 and Word 97
Worm? Macro Virus? Word 97 Virus? Word 2000 Virus? You Decide!
Word -> Email | Word 97 <--> Word 2000 ... it's a new age!
Melissa.b
This virus version transforms into a worm, not a virus: in its code, the global macros area and other documents infection routine is "commented" out (this code is present in the worm code, but all commands are disabled by "this is comment text" VisualBasic character). It is also mentioned in the author's comments in the worm's code: "We don't want to actually infect the PC, just warn them"
An infected document is attached to a message with:
Subject: "Trust No One"
Body: "Be careful what you open. It could be a virus."
When an attached document is opened, the worm-spreading routine takes control. It checks in the system registry for the "Melissa.a" mark, and if this is not present, the worm obtains one (first) address from each Outlook address list and sends new messages with itsown copy to these addresses. The worm then inserts the following text into the current document:
This could have had disasterous results. Be more careful next time you open
an e-mail. Protect yourself! Find out how at these web sites:
http://www.eos.ncsu.edu/eos/info/computer_ethics/www/abuse/wvt/worm/
http://www.nipc.gov/nipc/w97melissa.htm
http://www.cert.org/advisories/CA-99-04-Melissa-Macro-Virus.html
http://www.microsoft.com/security/bulletins/ms99-002.asp
http://www.infoworld.com/cgi-bin/displayStory.pl?990326.wcvirus.htm

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