What is adware and how do you get rid of it?
The term adware originated from the contraction of the terms advertisement (advertising) and software. Adware falls under the heading of malware and is primarily not dangerous, but very inconvenient, because the software can change the browser home page, brings unwanted advertising on the screen or installs a new toolbar. If you are annoyed by always new opening windows, you most likely captured one of these programs.
Adware is very unpleasant when while surfing or working on the internet when more and more browser windows load with unwanted (advertising) content, especially if those are sex or gambling sites, it can be embarrassing. Especially when the fiancé or the boss looks straight over the shoulder and when closing the browser window will open a whole armada of new (possibly even more unpleasant) windows.
It can get dangerous when the windows launch web pages with malicious code. What is particularly worrying is when opening a seemingly innocent link that results in other malicious programs to install subtly in the background. Such software can end up being trojans for remote access or control of the computer or the now frequent ransomware (programs that encrypt data and demand ransom, like one NetApp client found out).
How does a malicious program gets on my computer?
The adware authors are mostly to blame. Many free software packages come with this additional “software”. Then, a user can install a program without realising it, i.e. carefully reviewing the dialogue windows that are presented, for example in Adobe Flash Player, a free McAfee Security Program installed – the check box is checked here by default. So be aware: it is actually rare for an unwanted program to be presented as clear and visible as in the Adobe Flash Player case. Sometimes the check box is somewhat hidden so you'll you have to look carefully and read the instructions during installation. The so-called "default installation" is not generally recommended for free programs like these. Instead, always choose always the "custom installation".
Adware (or other malware) you get is often present on dubious sites with crack or key generators (keygen), i.e. websites designed to share expensive software without paying for it. If you run such a generator, a download will often start in the background and the computer is compromised.
But also real spyware can appear as adware on the PC. And this can come right out of the factory. In one case the computer manufacturer Lenovo had delivered new laptops with the adware "Superfish Visual Discovery" for months. This tool included a vulnerability to launch a man-in-the-middle attack by criminals, who then could engage in the communication between two computers unnoticed.
How can I delete such a malicious program?
Anyone who has ininvertently installed adware may see a few problems. Often the uninstall process is anything but trivial and hardly possible for the layman - which is desired by the author of the malicious program. Lucky, cautious users will have prepared their system so it frequently and automatically sets restore points. Such a system image can be easily selected and the computer is restored to a state prior to infection - wherein modified or newly stored data after that date is erased. A restore using a contemporary backup is another way – or a rebuild of the entire system, although in this case all data is then deleted.
The damage caused by adware can be minimised or prevented all together by other measures, if you respond quickly. First of all you should list all installed programs via the control panel of your operating system. The programs that you don't recognise or do not belong here should be removed. A tip: sort the list by clicking on the tab "installed on (date)", if available.
Then take a look at the extensions and plugins your browser used.
- In Firefox, you click on the menu icon (the three horizontal lines) and then click "add-ons". In the list under the menu item "extensions" you can erase any unnecessary additives – or at least deactivate them. Repeat the process under the navigation item "Plugins".
- In Internet Explorer, you find the Add-ons under the gear icon (“manage add-ons”).
- In Chrome, you also find the extension under the menu icon with the three lines.
If you still see strange ads, toolbars, or worse after taking these measures should consult an expert.