Today I turned no my PC and I faced an strange problem. Most of my documents and files such as .jpg, .pptx, .docx, .pdf where renamed with for example "xxxxxx.JPG.dslttdk" and "xxxx.PDF.dslttdk" and so on. I rename files and remove .dslttdk extension, but the contents are unknown yet. If I open them with Notepad, the contents are replaced with some strange characters like japanese characters. I have an updated antivirus, and I do not know how this problem has been appeared. Please help me with this corrupted .dslttdk! extension files.
I suspect that you have been hit by ransomware: malware that encrypts your files, requiring you to send a payment to hackers to obtain the decryption key. You probably need to reinstall your operating system and restore your data from backups. (You do have backups, don't you?)