{keyword}' Union All Select Null,null,null,null,null,null,null From Msysaccessobjects-- Nedi -

That string is a classic example of a attack payload [1]. Specifically, it's designed to probe or exploit an Access database (indicated by MSysAccessObjects ) [2, 3].

: It attempts to break out of a standard search or input field by adding a single quote [1]. That string is a classic example of a attack payload [1]

: The attacker is trying to match the exact number of columns used in the original database query [1, 4]. If the number of NULLs matches the number of columns, the page will load without an error, telling the attacker how many columns are in that table [4]. That string is a classic example of a attack payload [1]