CrowdStrike is a leading American cybersecurity company, that took the lead into the investigation of Russia's hacking of the Democratic National Committee's email back in 2016. As detailed in a recent ZDNet article, CrowdStrike has released a Global Threat Report for 2021, which illustrates how cyber criminals cooperate with one another.
Others focus on distribution by facilitating spamming or running traffic distribution systems. TDS systems direct users from one site to another from which malware can be installed.
Money mules are people who may believe they are working as a payment processing agent, but are in fact transferring funds sent by the victims of cyber attacks to the mule's bank account on to the hackers via Western Union which has a payment system that cannot be traced. Dump shops or CVV (card verification value) shops offer credit card account information for sale at around $20 per account, so others can prepare cards with the data.