Federal officials are warning people against malware attacks, which tend to ramp up during the holiday season.

Malware is a software that’s installed on devices without your knowledge, typically by scammers who convince you to click on a link or download infected software. It causes viruses and can be used to steal your personal information, like usernames and passwords, Social Security information or bank account numbers, warns the Federal Trade Commission.

Those behind the malware on your computer may also use it to hold your data for ransom and demand payment for its release.

The U.S. Federal Trade Commission said the best way to protect against the threat is to use security software and update it regularly.

READ MORE: Medicare alert: Feds issue open enrollment warning

The agency also recommends:

• Don’t click on a link in an unexpected email. Instead, contact the company using a phone number or website you know is real.
• Never call a phone number that appears in a pop-up window.
• Don’t click on ads to download software. If you see an ad for software that interests you, don’t click on it. Instead, go to the website by typing in the address.
• Don’t use unfamiliar websites to download free stuff like music, movies, shows, or games.

There are a few signs that your device may be infected with malware:

• Your computer slows down, freezes, or crashes.
• Your browser’s home page changes or automatically redirects you to sites you didn’t intend to visit.
• You notice new browser toolbars or add-on programs.
• You get a lot of pop-up ads, including some inappropriate ads or ads on sites you wouldn’t expect.
• You get repeated error messages from your operating system.
• Your operating system tools, like Task Manager or Activity Monitor, are disabled.
• You notice emails you didn’t write or social media messages you didn’t post.

Find more information on how to remove malware and report scammers here.