As Americans finish up their taxes before the April 18 deadline, cybercriminals are out in full-force trying to get some financial returns of their own.

According to a new report from IBM X-Force, tax-themed spam emails increased 6,000 percent from December 2016 to February 2017. In one of the most recent scams, cybercriminals are sending emails to the human resources and payroll departments of organizations across the country. These messages are spoofed to look like they're coming from an executive at the organization, asking for W-2s for the company's employees.

With this information, a crook would be able to file in your name and collect your return before you do. The report also notes that online miscreants have been selling W-2s and other tax information for around $40 to $50 a pop on the cybercriminal underground. HR and accounting employees who receive messages asking for W2s are advised to call the sender directly to authenticate the request.

Meanwhile, scammers are also sending individual taxpayers messages purporting to come from the IRS – a tried and true ruse. These emails falsely inform the recipient that their tax refund has been processed, and instruct the user to open a malware-laden attachment. Other messages are spoofed to look like they're coming from Turbo Tax in an attempt to get users to hand over their username and password for the service.

Criminals are also going after non-U.S. residents, claiming they can get a tax exemption by re-certifying. These messages ask recipients to provide a copy of their W-8BEN form and passport.

And don't think you're immune if you have already filed: IBM said that tax season scams will likely continue after the deadline has passed. "Criminals find ways to have more victims open malicious attachments under the guise of responses from their local tax authority," the report notes.

IBM's report comes after IRS along with state tax agencies last month warned tax professionals and taxpayers of phishing scams "requesting last-minute deposit changes for refunds or account updates." Always remember: The IRS does not send unsolicited emails or request sensitive data via email. Plus, you should never open an attachment or link from an unknown or fishy source. If you intend to file online via Turbo Tax or a similar service, go to the vendor's website directly.

If you have received a suspicious email, you can forward it to the IRS at phishing@irs.gov.