Gaelicum.A is a damaging computer trojan which exploits a bug in the Twitter messaging client and can enter your computer when you download malicious program file from the web. Gaelicum.A is also related to the fake anti-spyware XP Total Security. Once Gaelicum.A penetrates into your computer, it can open a backdoor to your system and enable a hacker to gain unauthorized remote access to the affected computer, infect files and even leave other nasty malware threats or invade user's privacy. Gaelicum.A will show "Windows cannot access the specified device, path, or file" message whenever you attempt to run any application. Remove Gaelicum.A as quickly as possible from your computer before it damages your computer and steal your personal data.