USERS of popular word processing and spreadsheet software such as Microsoft Word and Excel are under increasing threat from viruses being spread across the Internet. This is according to Team 400, a Dublin company which has just launched a new service designed to intercept email viruses before they reach users.
Although virus scanning software can cope with the majority of viruses introduced to a PC via the disk drive, its blind spot is email. Some virus scanners can detect email viruses - but usually only after the virus has reached the hard disk.
The email itself is safe, but "it is very easy for someone to add a virus as an attachment to an email," says Denis Neavyn, general manager of Team 400, which is part of the Trinity Group. "As soon as you click on it it's on your PC and you haven't had a chance to pre emptively check it."
He draws a parallel with being mailed a letter bomb. "There is very little you can do to protect yourself because the damage is done before you even realise it."
The main threat is "macro viruses", which use the macro facility in Word and Excel to execute routines automatically. In the worst cases, they can delete documents as soon as you open them or even erase files from your hard drive. The first, and best known of these is the Concept virus, which was created simply to make people aware of the dangers, but others are far less benign. "The macro virus looks exactly the same as a Word doc. Although macros supposedly only come as dot files, it is easy to change a T to a C," Neavyn explains.
To counter this, the Team 400 system diverts all email onto a safe semi standalone system, where the message is automatically decoded, scanned by several different virus scanners, and recoded, before being delivered to the recipient. If a virus is found, the message is isolated and the customer is warned that a virus was being sent to them. In some cases the sender is also warned, as they might have sent the virus without knowing it and their own PCs could be infected.
The system has just completed a three month trial with 20 customers in Ireland and Britain, during which it intercepted 30 viruses. Although this may not seem a significant number, Trinity Group director Jonathan Mills points out that "the numbers have been increasing, even during the course of the trial, and we believe the problem will grow as more businesses use the Internet."
This could prove expensive, particularly for the large semi state bodies, insurance companies and manufacturers which use Team 400. They would have to shut down their networks while each PC is checked and may find the problem is bigger than they thought, because many viruses don't reveal themselves for weeks, during which time they replicate themselves across the system and attach themselves to email, before suddenly wreaking havoc on a set date. Indeed, all those taking part in the trial have recognised its value and have opted to continue the service.
Unfortunately, this level of security isn't available to people using standard Internet service providers, but there are several simple, if tedious, things PC users can do to avoid the threat says Neavyn. First, only email with files attached (including zip or exe files) need worry you. Despite urban myths such as the Good Times hoax, you can't get a virus directly from email. If you don't know where a file comes from, don't accept it. And even if you do, save it direct to floppy disk, without opening it, then scan it with a virus checker as normal. Virus scanners can be bought from most dealers, and there are several good shareware versions available on the Net (but only take them from reliable sources).
Try Microsoft (http.//www.microsoft.com), and search for "macro virus" for specific cures, or try the CIAC archive (http://ciac.llnl.gov/), which is the best source for all information on viruses and general anti virus software. You can also contact Team 400 at info.team400.ie