Dogecoin, for those who don't spend their time indulging in Internet meta-memes, may seem like harmless nerdery. But for one enterprising hacker, it's created a small fortune—at the price of annoying a lot of systems administrators.

A pair of researchers at Dell's Secureworks security division have traced a collection of malware-infected storage devices to a hacker who has amassed more than $620,000 worth of the currency, which they say he mined from those hijacked machines and others. They say that stash, largely created in just two months earlier this year, may be the largest cryptocurrency hoard ever mined from the computers of unwitting victims. (Wow.)

"To date, this incident is the single most profitable, illegitimate mining operation," Pat Litke writes in a blog post explaining the findings. The two researchers concede, however, that they can only prove a small fraction of the coins were mined from the hacked storage boxes, and it's not clear what other machines—compromised or not—the hacker used to mine such significant Doge riches.

Litke and fellow researcher David Shear have spent months following a security vulnerability in storage hardware made by Taiwanese firm Synology. In September, security researcher Andrea Fabrizi found that the operating system used by such devices contained flaws that would allow a remote attacker to gain control of the machines and install malware. In February, Synology users began complaining that their devices were running slowly, and one Facebook poster noted that he'd found a folder on his machine labelled "PWNED."

In sample files shared online by infected users, Shear and Litke found a program known as CPUminer, used in mining cryptocurrencies like bitcoin. "That was the entrance to the rabbit hole," says Litke. "It became clear there was a significant amount of money being made off these Synology boxes."

While analyzing a config file in the "PWNED" folder, they discovered the mined currency wasn't being sent to a bitcoin address, but to one associated with dogecoin, a half-serious alternative to bitcoin that has since its launch in December become one of the most active cryptocurrencies. By checking the dogecoin blockchain (the public ledger of all dogecoin transactions), they could see all the coins mined at that address and at another address associated with the same hacker.+++inset-left

Dogecoin Foundation