{keyword}' And (select Char(121)||char(107)||char(70)||char(106) From | Information_schema.system_users)=char(103)||char(112)||char(87)||char(114) And 'mppv'='mppv

CHAR(103)||CHAR(112)||CHAR(87)||CHAR(114) translates to .

The query asks the database: "If the first characters of a system user name equal 'ykFj', is that equal to 'gpWr'?" Since these strings do not match, the query is likely being used as a test. An attacker monitors whether the application's response changes (e.g., a different error message or a successful page load) based on whether the injected condition evaluates to true or false. How to Protect Your Site CHAR(103)||CHAR(112)||CHAR(87)||CHAR(114) translates to

: This part of the query attempts to pull data from a system-level table containing user information. What This Payload Does How to Protect Your Site : This part

Are you seeing these queries in your or a specific application's search field ? : Restrict search inputs to a reasonable character

: These functions convert ASCII numeric codes into text characters.

: Restrict search inputs to a reasonable character length and filter out common SQL keywords.