Internet search giant Google is advising Gmail users in Iran to change their passwords and think twice before clicking on suspicious links.

Google warns that users’ accounts may be compromised by the fake SSL security certificates issued in wake of the security breach at the Dutch Certification Authority DigiNotar.

Google’s Eric Grosse recently said that they were directly making contacts with possibly affected users. He also claimed that users of the Google Chrome web browser were unaffected by the attack. However, he urged all Iranian Gmail users to take concrete steps to secure their accounts.

In July this year, hackers breached the computer of DigiNotar, a subsidiary of VASCO Data Security International Inc., and issued hundreds of fake certificates for third-party domains.

DigiNotar authenticates and registers SSL certificates, which make sure that traffic is accessing genuine Websites.

The fake SSL security certificates, which were also used for the domains of spy agencies such as the CIA, the MI6, and Mossad, can potentially provide hackers with access to users’ login credentials.