The value "1'"5000" is suspicious and resembles an attempt at SQL injection or other forms of injection attacks. Attackers often use payloads like "1'" to test for vulnerabilities related to improper input sanitization.

SQL Injection Testing: The single quote ' is used in SQL to denote string literals. An unescaped or improperly handled quote can break out of the intended query structure, allowing attackers to manipulate the SQL commands executed by your database.

Malicious Probing: By injecting such values into various headers and parameters, attackers probe your application's responses to see if it behaves unexpectedly, indicating a potential vulnerability.