1. 病毒：
病毒是附加到另一个可执行文件的恶意可执行代码，它可以是无害的，也可以修改或删除数据。当计算机程序运行时带有病毒，它会执行一些操作，例如从计算机系统中删除文件。远程控制不了病毒。
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。
病毒和广告软件的区别：
| S.No. | VIRUS | ADWARE |
|---|---|---|
| 1. | A Virus is a malicious executable code attached to another executable file which can be harmless or can modify or delete data. | Adware is similar to a spyware and it can be both intrusive and difficult to eradicate. |
| 2. | The main objective of virus is to modify the information. | The main objective of adware is to monitor your interests and display relevant ads. |
| 3. | Antivirus software are used for protection against viruses. | Adware can be detected and removed by the antivirus program. |
| 4. | It can control data and resources, cause error, destroy system and slow down the performance. | It provides profit to the developer by generating online advertisement. |
| 5. | Viruses are executed via executable files. | It is unknowingly attached with free to use software, distributed through pop-up windows. |
| 6. | Virus is more harmful. | Adware is less harmful than virus. |
| 7. | Resident and Non -resident viruses are two types of Virus. | Fireball, Appearch, Gator and dollarrevenue are some of the examples of adware. |