A team of security researchers at the University of Calgary are warning of a potential menace known as Typhoid adware.
According to associate professor John Aycock, Typhoid adware works in a similar fashion to Typhoid Mary, the first identified healthy carrier of typhoid fever who spread the disease to dozens of people in the early 1900s.
"Our research describes a potential computer security threat and offers some solutions. We're looking at a different variant of adware – Typhoid adware – which we haven't seen out there yet, but we believe could be a threat soon," Aycock told TG Daily in an e-mailed statement.
"Typhoid adware needs a wireless Internet café or other area where users share a non-encrypted wireless connection. [It is] designed for public places where people bring their laptops. [But it's] far more covert, displaying advertisements on computers that don't have the adware installed, not the ones that do."
Indeed, adware authors typically install their software on as many machines as possible.
However, Typhoid adware operates by "convincing" other laptops to communicate with it - rather than legitimate access points.
"The Typhoid adware [then] automatically inserts advertisements in videos and web pages on the other computers," explained Aycock.
"Meanwhile, the carrier sips her latté in peace – she sees no advertisements and doesn't know she is infected – just like symptomless Typhoid Mary."
Aycock added that his team had devised a "number of defenses" against Typhoid adware, including protecting the content of videos and increasing security awareness by "telling" laptops they are at an Internet café or public access point.
"When you go to an Internet café, you tell your computer you are there and it can put up these defenses. Anti-virus companies can do the same thing through software that stops your computer from being misled and re-directed to someone else.
"[Remember], not only are ads annoying but they can also advertise rogue antivirus software that's harmful to your computer, so ads are in some sense the tip of the iceberg."