1. 蠕虫：
蠕虫类似于病毒，但它不会修改程序。它越来越多地自我复制，导致计算机系统变慢。蠕虫可以通过远程控制。蠕虫的主要目标是吃系统资源。
2. 广告软件：
广告软件并不完全是恶意的，但它们确实出于恶意目的侵犯了用户的隐私。它们在计算机桌面或单个程序内显示广告(出现一个弹出窗口)。它们主要附带免费使用的软件，因此是此类开发人员的主要收入来源。他们基本上会监控您的兴趣并显示相关广告。攻击者可能会在软件中嵌入恶意代码，广告软件可以监控您的系统活动，甚至可以危害您的机器。
蠕虫和广告软件的区别：
| S.No. | WORMS | ADWARE |
|---|---|---|
| 1. | A Worm is a form of malware that replicates itself and can spread to different computers via Network. | Adware is similar to a spyware and it can be both intrusive and difficult to eradicate. |
| 2. | The main objective of worms to eat the system resources. | The main objective of adware is to monitor your interests and display relevant ads. |
| 3. | Worms can be detected and removed by the Antivirus and firewall. | Adware can be detected and removed by the antivirus program. |
| 4. | It doesn’t need a host to replicate from one computer to another. | It require host is needed for spreading. |
| 5. | It can give unauthorized access and control of the system to the hackers. | It provides profit to the developer by generating online advertisement. |
| 6. | It is less harmful as compared. | Adware is more harmful as compared. |
| 7. | Morris Worm, Storm Worm and SQL Slammer are some of the examples of worms. | Fireball, Appearch, Gator and dollarrevenue are some of the examples of adware. |
| 8. | Worms are executed via weaknesses in system. | It is unknowingly attached with free to use software, distributed through pop-up windows. |