Avoid Malware Scanners That Use Insecure Hashing

In this post I’m going to discuss a major problem that exists with several WordPress malware scanners: The use of weak hashing algorithms for good and bad file identification. Some malware and antivirus scanners outside of WordPress suffer from this same issue. For brevity, I’m going to refer to this as the “weak hash scanner” issue.
This issue may allow an attacker to hide malware that is undetectable to scanners using the MD5 hashing algorithm. Below I will explain how hashes are used in the security industry, what the problem is and how to solve it. I’ll also point you to research demonstrating this issue and further reading. I’ll also describe how Wordfence uses a secure hashing algorithm for our malware scanner.
How we use hashes in the security industry to find bad things
In the security world we have a commonly used process of running a file through a piece of logic, called an algorithm, and generating a unique number. That number is used to uniquely identify files. This process is called a hashing algorithm and the unique number is called a ‘hash’.
We use hashing algorithms for all kinds of really cool and useful stuff. We can
Source: https://managewp.org/articles/13966/avoid-malware-scanners-that-use-insecure-hashing

source https://williechiu40.wordpress.com/2016/12/06/avoid-malware-scanners-that-use-insecure-hashing/