Hackers penetrated network servers belonging to Opera Software, stole at least one digital certificate, and then used it to distribute malware that incorrectly appeared to be published by the browser maker. “The attackers were able to obtain at least one old and expired Opera code signing certificate, which they have used to sign some malware,” Wednesday’s advisory stated. It is possible that a few thousand Windows users, who were using Opera between June 19 from 1.00 and 1.36 UTC, may automatically have received and installed the malicious software.”