According to the Association of Certified Fraud Examiners, nearly 30 percent of businesses are victims of payroll malfeasance, with small businesses twice as likely to be affected than large businesses. Here are four scary payroll fraud schemes you need to know:

Ghost Employees.

A ghost employee does not exist anywhere except in your payroll system. Typically, someone with access to your payroll creates a fake employee and assigns direct deposit information to a dummy account so they can secretly transfer the money into their own bank account.

Time Thieves.

Time stealing happens when employees add more time to their timecard than they actually worked. Sometimes multiple employees will team up to clock each other in earlier than when they arrive or later than when they depart for the day.

Shape-shifting Commissions.

In an attempt to bump up a commission payment or attain a quota, sneaky sales employees may alter a sales contract to their benefit. A typical tactic used by a dishonest salesperson is to make a booked sale appear larger than it is and then slide a credit memo through the system in a later period. Companies with complicated commission calculations or weak controls in this area are the most vulnerable.

External Swindlers.

A popular scam, known as phishing, starts with a fraudster impersonating a company executive through email or over the phone asking an employee with access to payroll data to wire money or provide sensitive information. These imposters can make the correspondence look very real by using company logos, signatures and email addresses.

Tips to Combat Payroll Fraud

Being aware of the threats is a start, but you also need to know how to stop them. Here are some tips to reduce your companies payroll fraud risk:

Better Internal Controls.

While most employees are trustworthy, giving too much control over your payroll to one person is not a good idea. Separating payroll duties and formalizing an approval process protects both your business and your employees.

Review Payroll Records.

Designate someone outside of the payroll-processing department to periodically review the payroll records. Have them review names, pay rates and verify that the total payroll matches what was withdrawn from the business bank account.

Perform Random Internal Audits.

During an internal audit is when you can really get into the details to look for potential payroll fraud. You can do an in-depth review of the whole payroll system or select a random sample of dates and employees. Keep the timing of the audit under wraps to prevent giving someone the chance to cover up their misdeeds.