I subscribe to a thread ("Malware Removal Guides and Self Help Guides" ) at the Malwarebytes forum. As part of the information provided, they answer the question .. How did "____" get on my computer?
Most (not all) guides this year answer the question in the same way. "This particular one was bundled with other software" I don't post them. The below guide was posted today. I feet some of it is noteworthy. Especially, "How did Trojan.Agent Kryptik get on my computer?"
"Removal instructions for Trojan.Agent Kryptik"
What is Trojan.Agent Kryptik?
The Malwarebytes research team has determined that Trojan.Agent Kryptik is a Trojan Clicker. Typically these are used to perform online actions in order to boost hit-counts.
How do I know if I am infected with Trojan.Agent Kryptik?
There are hardly any visible signs unless you are actively looking. You may experience a slower then normal computer. Once you start looking what's wrong you may spot some oddly named folders in your %ApplicationData% folder. (The full path to this folder is usually C:\Documents and Settings\{username}\Local Settings\Application Data [Screenshot]
How did Trojan.Agent Kryptik get on my computer?
Trojans use many ways to infect your computer. This particular one was spread by using Silverlight and Adobe Flash exploits following this flowchart [Screenshot]
A full analysis of the exploit can be found on our blog.
Continued : https://forums.malwarebytes.org/index.php?/topic/157179-removal-instructions-for-trojanagent-kryptik/
[ Note: Underlining by me ]

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