On Thursday, TalkTalk issued a statement that an investigation was being launched by the Metropolitan Police Cyber Crime Unit, after the company suffered a "sustained cyberattack" on its website.
TalkTalk says there is a chance that the attackers were able to compromise names, addresses, birthdays, phone numbers, email addresses, TalkTalk account information, credit card data, and banking information.
"We are continuing to work with leading cyber crime specialists and the Metropolitan Police to establish exactly what happened and the extent of any information accessed," the telecom said.
"As soon as we realized the website was under attack, we pulled the site down in an effort to protect data...As a further precautionary measure, we contacted our customers straight away to warn them of the potential risk and provide advice on what to do."
TalkTalk also explained that not all of the data potentially compromised was encrypted. Other than stating their systems are constantly under review and updated to make them as secure as possible, the company didn't offer any additional details on the data that was and wasn't encrypted.
It's also unclear how many customers are impacted, as the company wasn't able to determine the full scope of the attack by the time it was announced on Thursday.
"We have been working around the clock with the police and cyber security experts to understand what happened, and what data was taken," TalkTalk said in an FAQ to customers.
The Information Commissioner's Office has been contacted about the incident, and TalkTalk says they have contacted major banks, which will be monitoring for any suspicious activity on customer accounts.
There are also plans to offer one-year of credit monitoring to all customers.
TalkTalk urged customers to watch for scams, and to remember that the company will never ask for personal information, passwords, or financial information over the phone or via email.
Earlier this year, TalkTalk customers complained about scammers using stolen information to entice people into releasing financial information. TalkTalk became aware that customer information was stolen after launching an investigation into the sudden rise in complaints over the scam calls.