As you may have heard, criminals used the Internal Revenue Service’s own website to steal taxpayer information for about 100,000 U.S. households, the agency said Tuesday, showing how vulnerable it remains as fraud proliferates.

The IRS will send you a letter if your records were at risk.

The criminals attempted to crack 200,000 accounts and made it into about half of them. The IRS will send you a letter if your account was among those 200,000, regardless of whether or not it was hacked. The agency will not call, email or send letters that ask for your personal information in response, but scammers might. Cyber thieves often take advantage of incidents like this by calling people and posing as taxmen , or emailing taxpayers malicious links.

Nasty links could infect your computer with malware in an attempt to steal your personal information, or lock up the machine until you pay a ransom — a tactic hackers began using this year while sending fake refund receipts to taxpayers, according to KnowBe4, a Clearwater, Fla.-based security company.

Source: IRS data theft: 5 things you need to know – MarketWatch