Ransomware is a form of extortion in which hackers lock computer files until victims pay money to regain access to their networks. Attacks have targeted individuals, large public companies, government agencies and nonprofit institutions such as hospitals.

If you’re hit by ransomware and don’t have backups, there’s usually little you can do other than pay the ransom. Companies that say they can recover your files with their own technology often just pay the ransom and charge you a fee on top of it.

While ransomware is one of the most common types of cybercrime, victims often don’t report attacks. As a result, federal crime statistics drastically underestimate its prevalence and impact. ProPublica is trying to go beyond the numbers. If you have inside knowledge of ransomware, or if your organization has been attacked, please fill out the questionnaire below.