MegaDownloader is a safe program even if your antivirus says otherwise. That’s at least what its developers state, who warn us that certain antimalware programs may detect it as a virus or as a Trojan container but that, in any case, that would be a false positive.
That’s due to the fact that to compress the file into the installation program, they have resorted to MPRESS, the formula that’ s also used by some viruses to be harder to detect. That’s why many security programs detect any application compressed using this method as malware or potentially dangerous software.
If you’re not too sure because you trust your antivirus more than your own mom, MegaDownloader’s official page recommends you to use an HTTP sniffer of the likes of Fiddler. The latter allows you to view what MegaDownloader does and how it connects to the Internet. Thanks to this tool, you’ll be able to check that apart from connecting to Mega to download files and look for new versions, it doesn’t establish any other connection with any other server and neither does it send any kind of personal information. And still, if you’ve got enough technical knowledge to do so, you can also try to analyze its source code to see for yourself that it doesn’t hide anything strange.
In any case, it’s never a bad idea to take precautions due to the large number of threats lurking all over the Internet, jeopardizing the safety of the users of different online services. The latter usually have to do with the theft of data and credentials with the intention to obtain some kind of financial profit.