With Easter two days away, email security firms are witnessing an expected uptick in ruses meant to capitalize on the religious holiday.

Security firm Symantec said it has spotted an outbreak in phishing emails claiming to include a 3-D Easter greeting card — when, in fact, the attachment actually contains malicious code. Mathew Nisbet, malware data analyst for Symantec Hosted Services, said in a Thursday blog post that the new 3-D hook appears to be an attempt to leverage pop culture interest in 3-D media to snare victims.

"Anyone who runs it hoping to see their card will be disappointed, as all they will get is an infected computer," Nisbet said.

Researchers also have seen changes to websites commonly linked to by spammers, Nisbet said.

"This is a common tactic for the people who create these websites, and the spam runs are developed to send victims there," he said. "The main site itself will stay the same, but a key banner in a central location gets updated with a seasonal or topical theme."

Users should take typical precautions and only trust emails from known sources, Nisbet recommended.