-1' OR 5*5=25 or 'NyqYC96j'='

This looks like a classic SQL injection payload. It’s designed to manipulate a query by injecting SQL via user input.

What it does (overview):

• The -1' ends a string literal in a query.
• OR 55=25 is a condition that is always true (in SQL, 55=25 evaluates to true).
• The rest (or 'NyqYC96j'='...) is meant to extend the injected part, often to bypass password checks.

If an application builds a query by concatenating user input, something like: SELECT * FROM users WHERE username = '$username' AND password = '$password'; and you substitute the input with -1' OR 5*5=25 or 'NyqYC96j'=', the WHERE clause can become tautological (always true), potentially letting an attacker bypass authentication or reveal data.

Defensive takeaways (exam-ready):

• Use parameterized queries / prepared statements. Do not concatenate user input into SQL strings. Example (pseudo-code): cursor.execute("SELECT * FROM users WHERE username = %s AND password = %s", (username, password))
• Validate and sanitize input, but don’t rely on escaping alone.
• Use least-privilege database accounts (no extra rights that could be exploited).
• Disable multiple-statement execution if your DB supports it, to prevent stacked queries.
• Use an ORM or stored procedures with proper parameter binding.
• Implement proper error handling to avoid leaking DB error details.
• Consider a Web Application Firewall (WAF) and logging to detect anomalous input patterns.

If you want, I can:

• Show a safe lab example of how this would fail in a vulnerable setup.
• Demonstrate how to fix a sample vulnerable snippet in your preferred language.