According to information released on the Dota-Allstars board, a new exploit made it into faked dota maps and general custom maps, that can cause immense damage on your systems by executing foreign code and installing trojans and viruses. Up till now there have only been reports about infected maps in public games. The problem has already been reported to Blizzards technical staff.

The map uses the same file/directory name as the originally map and displays an identical map preview. Because of the tiny size of the map (variing from 80 to several hundred kbs) and todays broadband connections in the majority of cases the downloading process will already be finished when you entered the game lobby, so you can hardly differentiate between healthy and dangerous versions.

One way to detect malware is to remove all maps from the download folder except for dota and keep the folder open when joining a game - if there`s a new file written into the folder its probably about a fake. Making the maps folder read-only has also worked out in single cases.

If you encounter hosted games at Dota-League, that are presumably hosted with corrupt versions, report as soon as possible.

Best regards,
Your Dota-League Team