Computer criminals seem to be stepping up their efforts to steal your personal and financial information—and your money.

The two most common approaches are the "tech support" scam, aimed primarily at individuals, and the "ransomware" scam, mostly used against businesses.

In a typical tech support scam, unsolicited phone callers say they are calling about "Windows," the popular operating system of computer software giant Microsoft. Don't believe it.

Microsoft says it never makes unsolicited phone calls about Windows computer problems.

Do not allow such a caller to take control of your computer. Hang up the phone immediately. This scam has been around since 2009.

Ransomware schemes have been around even longer, since 1989 when a disturbed biologist sent infected floppy discs to an AIDS conference sponsored by the World Health Organization.

This scam is aimed at businesses primarily because all it takes is for one employee to click on a link that then allows a scammer to take control of a business's computer system by shutting down the system or paralyzing it with encrypted, unintelligible jargon.

The scammer then demands a ransom, usually to be paid through an untraceable virtual currency such as bitcoin, to unlock the system and return it to normal.

The ransomware scam can start with a phone call much like the ones used by tech support scammers. In such a case, an employee is urged to allow the caller to obtain access to a business's computer system. Again, don't do it! Ever!

Today's version of the increasingly complicated scam also can start with a "phishing" email that asks a business computer user to click on a link to a website, article, or photograph that appears to be legitimate.

Scammers, in fact, are adept at creating legitimate-looking company names, fake caller IDs, and bogus company logos.

Business owners may be able to avoid these pitfalls by educating their employees about ransomware scams and how they work.

First, tell your employees never to take an unsolicited phone call from a stranger and then allow the caller access to your company's computer system.

Tell your employees not to rely on caller ID numbers to authenticate calls.

Also tell them about phishing emails that offer information or rewards if an enclosed link is clicked on.

Tell them never to click on a link from an unknown source, even if the email contains a legitimate-looking company name and logo.

If your employees don't know the source of an email, tell them not to click on a link or attachment – ever!