This rule is deprecated; use S4790 instead.
Why is this an issue?
The MD5 algorithm and its successor, SHA-1, are no longer considered secure, because it is too easy to create hash collisions with them. That is,
it takes too little computational effort to come up with a different input that produces the same MD5 or SHA-1 hash, and using the new, same-hash
value gives an attacker the same access as if he had the originally-hashed value. This applies as well to the other Message-Digest algorithms: MD2,
MD4, MD6, HAVAL-128, HMAC-MD5, DSA (which uses SHA-1), RIPEMD, RIPEMD-128, RIPEMD-160, HMACRIPEMD160.
Consider using safer alternatives, such as SHA-256, SHA-512 or SHA-3.
Noncompliant code example
SELECT HASHBYTES('SHA1', MyColumn) FROM dbo.MyTable;
SELECT HASHBYTES('SHA2_256', MyColumn) FROM dbo.MyTable;