Many companies have ghosts in their systems. Employees who've gone on to a better place -- say, with better pay -- but are still wandering through company files, cloud services, and social media accounts.
According to a study by Intermedia, 89 percent of adults retained access to at least one application from a former employer, and 49 percent actually logged into an account they weren't supposed to still have access to. Even more worrying, 45 percent retained access to confidential data.
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Last month, new numbers from the Labor Department showed that employees are on their way out the door again. With the improving economy, employees are no longer holding on to jobs at all costs, and the number of resignations hit levels not seen since 2008.
But there are a few things companies can do to protect themselves and their data, according to cloud applications company Intermedia.
1. Don't wait until the employees are gone
When an employee is first hired, it's nice to think that the relationship will last forever. But people grow apart.
Planning ahead for an employee's departure is a basic requirement for maintaining security after they leave. That includes making sure that the company has a record of all accounts an employee has access to, together with control over their login credentials.
And don't just plan ahead for your own employees. If your company has vendors or customers whose employees access your systems or documents, plan ahead for those employees leaving, as well.
For example, you might provide access based on work-based email accounts, if you are certain that the outside company automatically shuts down those accounts when employees leave.
2. Create a formal process to follow when employees leave
Most companies have this, said Levine.
"Whether it's a proprietor or an HR department person or someone in security, it's important to have a list of things you're going to go through when someone leaves," he said. "Make sure you get the keys to the front door, collect company credit cards, get the company laptop back."
That list needs to include shutting down access to all their corporate accounts, as well as accounts on company-related websites and services.
For small companies, this may require good recordkeeping and a great deal of discipline to keep the records up-to-date. Larger companies will have active directories.
3. Pay particular attention to cloud storage
Employees usually start using file-sharing sites for good reasons, Levine said. They need to be able to work on documents from home, or share them easily with colleagues, customers, or vendors.
"But once the information is in Dropbox in a personal account, there's not much the company can do about it," said Levine.
If employees need to share files to do their work, companies should provide access to a platform that has enterprise management functionality.
"Then the access can get taken away when the person decides to leave," said Levine.
4. Don't share accounts
Employees should not be sharing access to servers, networks, or cloud applications.
"Assign them each a separate login," said Levine.
When possible, connect cloud applications to your company's active directory, so you can easily turn off all access when employees leave the company.
"There are various cloud-based authentication services that integrate with active directory," said Levine.
Unfortunately, that's not always the case. A company might have only a single login for its Twitter or Facebook account, for example.
A single sign-on solution might help in these cases, logging into the cloud service on behalf of the employee, so that they never have to have access to the company social media account.
And if you don't have one?
"Be very disciplined about changing the passwords to all those resources when anyone leaves," Levine said.
5. Run regular audits
Even with the best practices in place, something can slip through the cracks.
That's why many companies run audits of their critical systems and resources.
"Every three to six or 12 months, go through the list of people who have access, and make sure that those people still work for you, and that they still need access to those resources," said Levine.