Trojan Vundo Dangerous Virus are examples of trojans that infect your computer, often after you clicked on a .exe file. What are .exe files? These files often impersonate certain files that look like patches to a software that you were looking for. They are small size in nature, often less then 1mb and once installed, can be difficult to remove.
Trojan Vundo has many variations. This code is often detected by the traditional Norton anti virus. However, although it can be detected, the removal is not easy. Often you'll clean, then reboot only to find that the trojan is still present. You will know this when the trojan symptons are still around. Trojan Vundo symptons include having multiple pop up advertisments appear on your Internet Explorer while you surf the web. Other variations of Trojan Vundo open back doors to your PC and this allow a hacker to potentially run other types of trojan on your computer, such as Keylogger, that detect usernames and passwords of sites you visit.
Some trojans impersonate Dangerous virus. What you'll see is a large box, warning message that displays when you do a search on Google. It will ask you to purchase their trojan removal tool. The problem with this is that if you install their software, this can open up more trojans to your computer. I've found that Norton, AVG tools can detect but can't easily remove this problem.
In order to take care of your computer security, you'll want to not download and open any attachments, even if its from an email that you're familiar with. This is because emails can impersonate trusted addresses while attaching malicious trojans. You can often spot an email that is potentially dangerous by the contents. If its too short, or say something like "Hey check this out". you might not want to open it.
Lastly, having a good Trojan Anti Virus Removal tool installed on your computer, will warn you when it detects malicious file attachments on your mailbox.
