It goes by names like WannaCry, Locky, and CryptoLocker, and if the computers in your workplace were infected with one of these, or the many other variants of ransomware, you would know almost immediately. It generally starts with an email that asks you to download and open an attachment or enable macros on a document. Once you comply, the malware starts running in the background and encrypting all of your files using asymmetric encryption so that you cannot open and view them without the decryption key. Of course, that key is only made available to you once you pay the hacker the ransom; details for payment are made available to you via the new background the malware has set up on your computer.