Banker Trojans are especially written pieces of malware that have a sixth sense. They remain dormant for most of the time and only wake up when the user points their browsers to bank sites the malware is instructed to monitor. When they see it, they perform miscellaneous tricks to intercept the entered credentials and then report back to the base. Bankers would rather perform one of the two types of attack called Man-in-the-Browser and browser hijacking. The only drawback in the way the malware works is the pretty bulky size of the application itself.”]
Source: https://www.bitdefender.com/blog/hotforsecurity/banker-trojans-whos-been-spying-on-you-lately/