Microsoft Malware Protection Center (MMPC) is now Windows Defender Security Intelligence (WDSI). Watch out for even more info about threats and protecting you and your Windows computer.
Alert level: Severe Detected with Windows Defender Antivirus
Also detected as: Trojan-Ransom.Win32.PornoBlocker.bho (Kaspersky) W32/Ransom.KB (Norman) Trojan.PornoBlocker!CvjyYihPT7M (VirusBuster) TR/Ransom.PornoBlocker.bho (Avira) Win32/LockScreen.XU (ESET) Trojan-Ransom.Win32.PornoBlocker (Ikarus) TROJ_RANSOM.FP (Trend Micro)
The threat locks your screen and prevents you from using your desktop. It shows you a message saying that if you want to regain access to your desktop, you have to pay a fine in the form of an SMS sent to a premium number.
This type of threat is known as ransomware.