Cloud-based Services Vulnerabilities Also Used in Targeted Attacks

Recently, Trend Micro researchers encountered a potential vulnerability that affected users of Yahoo! Mail. We discovered several emails used in targeted attacks that contained JavaScript in the “From” field that attempted to launch a Document Object Model (DOM)-based cross-site scripting attack against the recipients of the email. However, we were not able to replicate the attack successfully. We have been in touch with Yahoo! about this problem.They, too, were unable to replicate this attack successfully at that time. However, to protect users against any such problems Yahoo! has strengthened their filters that sanitize user emails in order to protect against these kinds of attacks.

This is not the first time that vulnerabilities have been found in popular webmail providers. We discussed almost a year ago that some of the major webmail providers – Gmail, Hotmail, and Yahoo! Mail – were all found to have some sort of vulnerability that compromised either the user’s email account or their system. It shouldn’t be a surprise that they’ve become targets as well: just about everyone uses these free services, and users don’t expect these services to have security problems of their own.

As we’ve highlighted before, vulnerabilities like these are used in targeted attacks. Whether it’s vulnerabilities in user software or cloud-based services like free webmail, vulnerabilities allow attackers to compromise systems without the target being aware that anything has happened. This is extremely useful to attackers as the content compromised email accounts can be stolen by attackers and the account can be used to launch further attacks against the victim’s contacts.

Post from: TrendLabs | Malware Blog – by Trend Micro