User Guide

Preface
xviii Dr Solomon’sAnti-Virus
Macro viruses
By1995orso,theviruswarhadcometosomethingofastandstill.Newviruses
appeared continuously, prompted in part by the availability of ready-made
virus“kits”thatenabledeven somenon-programmersto whipupa newvirus
innotime. Butmost existing anti-virussoftware easily kept pacewithupdates
that detected and disposed of the new virus variants, which consisted
primarily of minor tweaks to well-known templates.
But 1995 marked theemergence ofthe Concept virus, which added a new and
surprising twist to virus history. Before Concept, most virus researchers
thought ofdata files—the text, spreadsheet,ordrawing documents createdby
the software you use—asimmune toinfection. Viruses,after all, areprograms
and, as such,needed to run in the same way executable software did in order
to do their damage. Data files, on the other hand, simply stored information
that you entered when you worked with your software.
That distinction melted away when Microsoft began adding macro
capabilities to Word and Excel, the flagship applications in its Office suite.
Using the stripped-down version of its Visual Basic language included with
the suite, users could create document templates that would automatically
format and add other features to documents created with Word and Excel.
Other vendors quickly followed suit with their products, either using a
variation of the same Microsoft macro language or incorporating one of their
own. Virus writers, in turn, seized the opportunity that this presented to
conceal and spread viruses in documents that you, the user, created yourself.
The exploding popularity of the Internet and of e-mail software that allowed
userstoattachfilestomessagesensuredthatmacroviruseswouldspreadvery
quicklyandverywidely.Withinayear,macrovirusesbecamethemostpotent
virus threat ever.
On the frontier
Even as viruses grew more sophisticated and continued to threaten the
integrity of computer systems we all had come to depend upon, still other
dangers began to emerge from an unexpected source: the World Wide Web.
Once a repository of research papers and academic treatises, the web has
transformed itself into perhaps the mostversatileandadaptable medium ever
invented for communication and commerce.
Because its potential seemsso vast,the webhas attracted the attentionand the
developmental energies of nearly every computer-related company in the
industry.