NEW YORK (CBSNewYork) – As cyber threats grow more sophisticated, questions are being raised about the value of anti-virus software that cannot detect stealth attacks.

Antivirus software works by scanning for files that are recognized by the computer’s database of attack software, reports CBS2’s Siobhan Gorman.

When suspicious code is found, the software quarantines or deletes malicious files.

Nearly 40 percent of successful cyberattacks last year occurred on computers that had antivirus software, according to the security firm, Malwarebytes.

Anti-Virus Reviews From CNET.com

The problem is that most cybercriminals now test their attacks against common antivirus programs to make sure they can get past them.

An antivirus program is only a first line of defense, so it’s also important to take additional security measures like using strong passwords and updating programs on your computer with the latest security patches.

Should you ditch your antivirus software? Experts say no, a good anti-virus program is necessary.

They also provide additional security layers such as protections against ransomware, email and banking attacks, as well as parental controls.

SEE: CNET’s Security and Antivirus Center

Make sure you download your antivirus program from a trusted site, as the last thing you want to get from your antivirus program is a virus.