The US-CERT is aware of public reports of malicious code circulating via spam email messages related to the IRS. The attacks arrive via an unsolicited email message and may contain a subject line of “Notice of Under-reported Income.” These messages may contain a link or attachment. If users click on this link or open the attachment, they may be infected with malicious code, including the Zeus Trojan.

Users and administrators are encouraged to take the following measures to protect themselves:

• Review the How to Report and Identify Phishing, E-mail Scams and Bogus IRS Web Sites document on the IRS website.
• Do not follow unsolicited web links or attachments in email messages.
• Maintain up-to-date antivirus software.
• Refer to the Recognizing Email Scams article.
• Refer to the Avoiding Email Scams article.
• Refer to the Avoiding Social Engineering and Phishing Attacks article.

The United States Computer Emergency Readiness Team (US-CERT) is a partnership between the Department of Homeland Security and the public and private sectors. Established in 2003 to protect the nation’s Internet infrastructure, US-CERT coordinates defense against and responses to cyber attacks across the nation.