BT's customer services' Twitter account has been used to spread a phishing attack.
Twitter users have been claiming that BT Care has been hacked, but BT said this is not the case.
"The BT Care Twitter account has not been hacked. There is a suspected phishing attack which has affected a small number of our followers," said a BT spokeswoman.
BT is warning its followers to be cautious when clicking on Tweets.
Phishing attacks are a way for fraudsters to trick people into giving away their personal details. These attacks are usually disguised as messages from banks.