6.1.6.2.1. Significantly increased network usage

6.1.6.2.1.2. Mass Mailing Worm

6.1.6.2.1.1. Network Service Worm

6.1.6.2.1.3. Backdoor

6.1.6.2.1.4. E-mail Generators

6.1.6.2.1.5. Bot/Downloader