Equifax, one of the three major credit rating agencies in the U.S., has been hit with a data breach that has compromised the personal details of up to 143 million consumers.
The company announced the "cybersecurity incident" on Thursday, saying details of almost half of U.S. citizens were compromised by the breach.
Sensitive information including social security numbers, names, birth dates, addresses and some driver's license numbers have been accessed by the cyber criminals.
The credit card numbers of around 209,000 consumers have been stolen too, along with other documents with personal identifying information for around 182,000 people.
The breach started mid-May with the hack eventually discovered on July 29.
Since Equifax is one of the three credit-reporting companies that track and rate the financial histories of consumers, the 143 million affected likely represent the bulk of U.S. adults.
Equifax, along with competitors Experian and and TransUnion, get information about loans, credit cards, rent and utilities payments, along with a whole host of other information, to determine your credit score.
In many cases people might not be aware they're customers of the company, as Equifax gets its data directly from banks, lenders, retailers and landlords who report activity to rating agencies.
How to know if you're affected?
The first thing to do is check this dedicated site Equifax has created to see if your data is among those compromised.
You'll be asked to enter your last name and the last six digits of your social security number to determine if your data has been stolen.
Equifax is offering free identity theft protection and credit file monitoring to ALL U.S. consumers, even those not impacted, to protect you from attempts to steal your identity or open lines of credit in your name.
More information on this can be found here.
Those whose credit card details were compromised will receive notices from Equifax informing them of this.
Going forward, consumers are urged to keep a close eye on their bank and credit card statements on a regular basis.
Matt Schulz, senior industry analyst at CreditCards.com, told CNN. "Bad guys can be very patient, so it's important to keep an eye out long after this story fades from the headlines."