A new Trojan horse demands a $10.99 ransom payment to stop erasing files on the infected PC’s hard drive, a firm said Thursday.

According to U.K.-based Sophos, the Ransom.a Trojan freezes the computer, then puts up a message saying it will delete files every half hour until the user sends $10.99 via Western Union to a designated account.

Read more: Trojan Demands $10.99 Ransom To Free Files