The credit reporting agency, Equifax, has revealed that they suffered a huge cyberattack that could affect up 143 million Americans.

The hackers gained access to sensitive personal data, including social security numbers, birth dates and addresses of nearly half the population of the US.

The company released a statement on their website saying: “Based on the company’s investigation, the unauthorized access occurred from mid-May through July 2017.”

On September 7 Equifax publicly confirmed that a breach occurred, but has so far refused to disclose why it waited six weeks before disclosing the cyberattack.

In addition to gaining access to personal data, the cybersecurity breach also exposed 209,000 credit card numbers that also includes customers from Canada and the UK.

Equifax is one of the largest credit reporting agencies in the US and analyze financial data records that cover a wide range of consumers from around the world. They often get this information from credit card companies, banks and lenders. They then use this data to determine a person’s credit score.

In a video posted on their website, Rick Smith, Chairman and CEO of Equifax, said, “This is clearly a disappointing event for our company, and one that strikes at the heart of who we are and what we do. I apologize to consumers and our business customers for the concern and frustration this causes.”

The Atlanta-based company also announced that they will be contacting all those affected by mail and have set up a website, equifaxsecurity2017.com, and a dedicated call center to deal with consumer concerns.

While the numbers possibly affected is staggering, it's still dwarfed by the data breach suffered by Yahoo when more than 1 billion users' accounts were breached throughout the world.

In further developments, Bloomberg News reported that three senior executives - Chief Financial Officer John W. Gamble; Joseph M. Loughran III, the president of US information solutions; and Rodolfo O. Ploder, the president of workforce solutions - sold shares worth almost $1.8 million shortly after Equifax discovered the security breach.

The company did confirm that the trio had no knowledge of the incident before they sold their shares.

Equifax shares fell 13% after news of the cyberattack was announced.