Scandinavian browser maker Opera Software was the recent victim of a hacker
attack in which the infiltrators made off with at least one old and expired Opera code signing certificate. The attackers were then able to use the certificate to sign some malware
and distribute malicious software under the pretense that it's been published by Opera Software, or appears to be the Opera
browser, the company said.
Fortunately for Opera browser users, Opera Software doesn't believe that any user data was stolen or otherwise compromised in the attack, adding that current evidence suggests the attack had "limited impact."
"On June 19th we uncovered, halted, and contained a targeted attack on our internal network infrastructure," Opera Software stated in a blog post. "Our systems have been cleaned and there is no evidence of any user data being compromised. We are working with the relevant authorities to investigate its source and any potential further extent. We will let you know if there are any developments."
As for the malicious code, Opera Software said it's possible that a "few thousand Windows users" running Opera between 1:00 AM and 1:36 AM UTC on June 19th may have automatically received and installed a bogus update. All Opera browser users are encouraged to update to the latest version.