The Internal Revenue Service (IRS) is warning taxpayers about a snowballing email attack that uses messages pretending to be legitimate IRS communications. The end game for the effort is malware being installed on unsuspecting users’ machines; imposters may gain control of the taxpayer’s computer or secretly download software that tracks every keystroke, eventually giving them passwords to sensitive accounts, such as financial accounts.

The gambit starts with messages to taxpayers from email addresses that spoof legitimate IRS addresses. The emails contain a link to a spoofed IRS.gov website that displays fake details about the targeted recipient’s tax refund, return or account.

The fake emails have subject lines like “Automatic Income Tax Reminder” or “Electronic Tax Return Reminder.” They claim to contain a “temporary password” or “one-time password” to access the files purportedly needed to submit a request for a refund or for information. However, those files are actually just malware in disguise.