Mark Gasson had caught a bad bug. Though he was not in pain, he was keenly aware of the infection raging in his left hand, knowing he could put others at risk by simply coming too close. But his virus wasn't a risk for humans. Gasson, a cybernetics scientist at the University of Reading, was walking around with an implanted microchip he had intentionally infected with a computer virus. If he got too close to a computer, he could in principle infect that machine.

Although this possibility may sound like a foray into science fiction, information security experts believe the blurring of the boundaries between computer and biological viruses is not so far-fetched—and could have very real consequences.

As TechWorld reports, Axelle Apvrille and Guillaume Lovet of the network security company Fortinet presented a paper comparing human and computer virology and exploring some of the potential dangers at last week's Black Hat Europe conference.

Both computer and biological viruses, they explain in their paper, can be defined as "information that codes for parasitic behavior." In biology, a virus's code is written in DNA or RNA and is much smaller than the code making up a computer virus. The DNA of a flu virus, for example, could be described with about 23,000 bits, whereas the average computer virus would fall in a range 10 to 100 times bigger.

The origins of each virus are strikingly different: A computer virus is designed, whereas a biological virus evolves under pressure from natural selection. But what would happen if these origins are switched? Could hackers code for a super-virus, or a computer virus emerge out of the information "wilderness" and evolve over time?

Apvrille and Lovet argued that both scenarios are possible, with a few caveats to each. Scientists have already synthesized viruses such as polio and SARS for research purposes, so it's conceivable that someone could synthesize viruses as bioweaponry. That said, Apvrille and Lovet observed that viruses are notoriously difficult to control, and it's hard to imagine anyone could use a viral weapon without it backfiring.

As for computer viruses speciating and evolving, Apvrille and Lovet believed that with enough data the code for a single computer virus might form spontaneously. Chances are slimmer, however, that it would include the necessary details to adapt and evolve. So far this scenario has only occurred in viruses in which researchers have encoded genetic algorithms to mimic evolutionary processes.

But there are more immediate possibilities for computer-biology crossovers. Synthetic biology uses computers to store genetic information, and Apvrille and Lovet explained that hackers could infect these devices or the software used for DNA sequencing, thereby modifying whatever biological product is being synthesized.

For now, Mark Gasson's example of an infected implant may spark the most concern, as it illustrates how cybernetic technologies leave humans vulnerable to unprecedented attacks. Just as a PC can download a virus after visiting a new website, cybernetic devices, such as cochlear implants or pacemakers, could be threatened when they connect to an external system. Once infected, the implant can then spread the virus to other systems.

Inevitably, as we rely more on computers, the impact of viruses grows. After all, our favorite technologies are extensions of ourselves, storing memories, expanding our knowledge and increasing our reach. As Gasson put it on his online Q&A about the study, even though the experiment had no effect on his health, it was still "surprisingly personal," because "part of 'me' had been compromised."