The Better Business Bureau are recommending those affected by the recently discovered Excellus data breach act quickly to avoid potential identity theft.

Rochester-based Excellus BlueCross BlueShield and related companies (Lifetime Benefit Solutions, Lifetime Care, Lifetime Health Medical Group, The MedAmerica Companies and Univera Healthcare) was the target of a cyberattack that may have compromised the personal information of over 10 million people, including St. Lawrence County residents.

Many of those people who could be affected are in upstate New York, the BBB said.

The data breach happened Dec. 23, 2013 and was discovered in early August of this year, Excellus CEO Christopher Booth said.

It wasn’t reported to the public until Wednesday.

Excellus is starting the process of mailing letters to people who may be affected. Better Business Bureau of Upstate New York says they advise those who may have been compromised to not take a “wait and see approach.”

“You must act quickly. Breaches involving personal information have the potential to be far more detrimental to victims, and the damage can be difficult to repair,” BBB said.

The group suggests people should consider taking a preemptive strike by freezing credit reports. This will not impact existing credit cards and financial accounts, but will create a roadblock for thieves seeking to create fraudulent accounts using one’s personal information.

Those who know their Social Security number has been compromised should place a fraud alert on their credit reports. While less effective than a freeze, this will provide an extra layer of protection, BBB said.

Anyone who’s data may have been compromised should take advantage of any free credit monitoring services being offered by Excellus to breach victims. While this is not a preventative measure, this will alert to new accounts or inquiries using a Social Security number so the person can act quickly to repair the damage, BBB said.

“Vigilance is critical. Regularly check your credit reports at annualcreditreport.com for unauthorized charges or other signs of fraud,” BBB said.

For more information and complete step-by-step guidance on repairing the damage caused by identity theft, visit the Federal Trade Commission’s identity theft resources, BBB said. Excellus has also set up a website for people who may be affected at excellusfacts.com.