I think that the win 32 malware.gen couldn't have any detailed description 'win32' a Windows 32bit application, 'malware' could mean almost anything (hard to define) with potentially malicious intent and '.gen' = Generic, a generic (non-specific) detection.
Malware Defined
Malware is the collective name for a number of malicious software variants, including viruses, ransomware and spyware. Shorthand for malicious software, malware typically consists of code developed by cyberattackers, designed to cause extensive damage to data and systems or to gain unauthorized access to a network. Malware is typically delivered in the form of a link or file over email and requires the user to click on the link or open the file to execute the malware.
Malware has actually been a threat to individuals and organizations since the early 1970s when the Creeper virus first appeared. Since then, the world has been under attack from hundreds of thousands of different malware variants, all with the intent of causing the most disruption and damage as possible.
As for the file rep malware, it is a file with a low reputation or first time seen by Avast. Again the dreaded almost undefinable 'malware' word creeps in.
There are literally millions of virus signatures, currently 16,818,927 even harder to define individually, as individual signatures can detect multiple samples.
