Yahoo! Inc. co-founders Jerry Yang and David Filo celebrate the launch of the new Yahoo! Mail in Sunnyvale California
Yahoo and Microsoft's Hotmail are the latest targets for hackers. The attackers were partially successful in compromising the Yahoo accounts REUTERS/Ho New

Microsoft’s Hotmail and Yahoo! Mail have also been targeted by hackers, an online security firm reported.

Trend Micro said, its research team in Taiwan has exposed a phishing attack over Hotmail and attempted to steal users’ cookies in Yahoo Mail. The attacks were similar to that of Gmail, it said.

“Trend Micro recently uncovered a malware that also uses the res:// protocol to enumerate the software installed in targets’ computers, setting the stage for future, more precise attacks. Once the attackers know what softwares are installed on a target’s computer, including antivirus products, they can craft a precise attack targeting any vulnerable software. Such an attack will then have a high probability of success,” wrote Nart Villeneuve, Senior Threat Researcher, in the company’s official blog.

The company said in case of Yahoo Mail, the hackers were not completely successful but it did signify that hackers are looking for a way to compromise Yahoo mail accounts.

These attacks were first revealed in February by Mila Parkour, a researcher. She found that apart from monitoring the compromised users’ email account, the attackers also utilized a script that exploits the the res:// protocol to itemize the type of antivirus software the victim has installed on his/her system.

“These events demonstrate that in addition to targeted attacks that encourage users to open malicious attachments, usually .PDF and .DOC files, attackers are also attempting to exploit vulnerabilities in popular Webmail services in order to compromise Webmail accounts, to monitor communications, and to gain information in order to stage future attacks,” added Villeneuve. “We recently alerted Yahoo! of an attempt to exploit Yahoo! Mail by stealing users’ cookies in order to gain access to their email accounts.”

The company said it is difficult to defend against such threats as these often appear to come from identifiable sources. However, there are some clues which can be helpful to find out about these attacks which generally come in the form of spelling and grammatical errors, the company website reported.