Here at WoW Insider, we've noticed an unusual and disturbing glut of people having trouble with being keylogged or otherwise hacked soon after installing new addons lately (which wouldn't be a surprise -- lots of people were grabbing addons after patch 2.4, so that makes them a likely route for attackers). While it's too early to make any definite connections, It seems like there's one new lead that's just popped up: popular addon site wowui.incgamers.com (not linked for obvious reasons) is apparently passing off bad files, according to reports from Stopbadware.org and other anonymous sources.
If you've been using the site for your addons, especially in the past week or so, it might be a good idea to exercise some caution and run your favorite anti-virus or anti-malware program. The site has already been in trouble recently with reports that their UICentral addon updater (now discontinued) was using copyrighted code, and now it looks like there's more trouble abrewing for them.Update: Wowui.incgamers not infested with malware. Full story here.