The deadline for filing your taxes was April 15, but tax scammers have no deadline.
In a quest for personal information and money even after filing deadlines, scammers often impersonate the Internal Revenue Service (IRS).
"The IRS encourages taxpayers to be vigilant year round against phone and email scams that use the IRS as a lure," the IRS said in a statement e-mailed to CNBC.com. "These scams won't likely end with the filing season so the IRS urges everyone to remain on guard," the IRS said in the email.
Can you trust caller ID?
Since October, the IRS has been warning Americans about a sophisticated phone scam that remains pervasive and frequently targets immigrants. The scam has cost the victims more than $1 million, and there have been roughly 20,000 reports of the scam, according to a Treasury Inspector General for Tax Administration press release.
The scam begins with a phone call claiming to be from the IRS. Usually the scammer will say either the call recipient is entitled to a big refund, or they owe money that must be paid immediately. If the recipient refuses to pay, the scamming caller often becomes hostile and threatens jail time or a revocation of the individual's drivers' license.
The phone scam is so sophisticated that the scammers are able to outsmart caller ID technology so that the IRS's number appears. Adding to the appearance of legitimacy, the scammers will offer fake IRS badge numbers and often know the last four digits of the victim's Social Security number.
When receiving one of these calls, "people have to step back and take a deep breath," said Laura Iwan, senior vice president of programs for the Center for Internet Security, a nonprofit that focuses on cybersecurity. She suggests targeted individuals immediately contact the IRS to see if the original call was legitimate.
Other signs the call may be from a scammer include the caller asking for payment using a pre-paid debit card or wire transfer, or asking for a credit card number. The IRS will not ask for this type of payment, nor will they ask for your credit card number over the phone.
Additionally, the IRS's primary correspondence method is through the U.S. Postal Service.
Watch out for phishing emails
While the phone scams are a new threat, phishing emails continue to be a pervasive scam tactic. These phishing emails sometimes contain links to websites that are infected with malware, and purport to be from the IRS and try to convince you to volunteer your personal information.
"We definitely see more phishing, often with a malware component [after April 15]. The messages may pretend to be from the IRS, or one of the popular companies people tend to use for e-filing their taxes," said Roel Schouwenberg, principal security researcher at Kaspersky Lab in an email to CNBC.com.
Like the scam phone calls, these phishing emails will either promise the taxpayer a refund or claim the taxpayer owes money and usually threatens dire consequences if not paid, said Iwan of the Center for Internet Security.
The IRS will not initiate contact with taxpayers by email or any other form of electronic communication. If you receive an email claiming to be from the IRS, you should avoid clicking on any links or opening any attachment. You should also report the email to the IRS by forwarding it to phishing@irs.gov.
Be careful where you store your taxes
More than 90 percent of Americans now electronically file their taxes, according to the IRS. While computers have expedited tax return preparation, security experts warn they are a risky place to store your personal tax data.
"Tax returns are a treasure trove. They contain everything someone needs to steal yours and your spouse's identity. They can be easily stolen," Schouwenberg said.
Iwan suggests once you file, store your taxes on an external hard drive or flash drive. You should also make sure you have up-to-date anti-virus, anti-malware, and firewall software.
If you believe you are the victim of identity theft, contact the IRS Identity Protection Specialized Unit at 800-908-4490, extension 245.
—By CNBC's Jennifer Schlesinger. Follow her on Twitter @jennyanne211
For more CNBC coverage of cybersecurity, visit HackingAmerica.cnbc.com.
