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

: This is used to combine the results of the original intended query with data from a second query that the attacker controls [1].

: This targets a system table in Microsoft Access that contains information about database objects [2, 3]. : This is used to combine the results

: This is a comment symbol used to "ignore" the rest of the original code, preventing syntax errors [1]. : This is used to combine the results

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]. : This is used to combine the results