Here the name of the game is to grab your personal login and password data with a "Form grabber" as you enter it into your bank or other online system. This information consists of your stolen credentials, the timestamp of when you visited a site, which Web sites you visited, and possibly your Web browser's cookies. Finally, all this is then passed on over the Internet to a command-and control server. From there the crooks can get to work selling your information to people who will start running up your credit-card bills.

At this point, some Linux users may start pooh-poohing this as yet another case of virus FUD. It's not. Hand of Thief really is out there. I should know. Someone tried to give a case of it to me earlier today.

By the way, that wasn't a mistake when I said "sales agent." Like a lot of modern malware, Hand of Thief is designed by criminals for criminals. As Kessem wrote, "This malware is currently offered for sale in closed cybercrime communities for $2,000 USD (€1,500 EUR) with free updates." When it goes "commercial," its "price is expected to rise to $3,000 USD (€2,250 EUR), plus a hefty $550 per major version release. "

While it might be a threat to Linux users wouldn't the numbers of linux users be relatively low? I thought that most Linux machines are servers.

A lot of government machines in other countries & defence personnel machines are Linux (so they're not reliant on a single vendor).
Developing countries also can be heavily reliant on Linux due OEM MS costs.