### Comment:
What are some common techniques used in malware propagation?

### REPLY:
One common technique used in malware propagation is to exploit zero-day vulnerabilities, which are unknown vulnerabilities in software that have not yet been patched. Another technique is to create botnets, which are networks of infected computers controlled by a central command and control server. These botnets can be used to distribute malware to a large number of computers simultaneously. Additionally, malware authors may use spam emails with malicious attachments or links to infect unsuspecting users' systems.