Updated version of STOP Ransomware ransomware appends .PAUSA, .CONTACTUS, .DATASTOP or .STOPDATA suffixes to encrypted files. Virus still uses RSA-1024 encryption algorithm. All versions, except .STOPDATA, demand $600 ransom in BTC (BitCoin cryptocurrency), last one offers decryption for $200. Still malefactors offer to decrypt from 1 to 3 files for free to prove, that decryption is possible. This can be used to attempt decoding in future. At the moment, unfortunately, the only way to restore your files is from backups.