"The Symantec Security Response team has received multiple reports of the hijacking of Yahoo! instant messaging accounts over this past weekend. The hijacking seems to be successful because some users are unwittingly providing their Yahoo! login credentials to a phishing Web page. There are several phishing Web pages involved in the attacks, some of which are listed here:
Please use caution when receiving instant messages with links included in the text, especially any links that require you to login to another Web site. This phishing attack will attempt to use valid and current (compromised) Yahoo! accounts so that messages sent will appear to come from trusted contacts, so you'll need to keep a keen eye out for strange messages. For a detailed explanation on how this attack is carried out, please refer to my previous blog entry that describes the IM Phishing Threat."