-1' OR 5*5=26 --

It looks like an SQL injection-related fragment. Here’s a quick breakdown of the pieces:

-1' — the single quote is typically used to try to break out of a string literal in a SQL statement. OR — adds another boolean condition to the WHERE clause. 5*5=26 — this evaluates to false (25 = 26 is false). -- — starts a SQL comment, so the rest of the line is ignored.

What effect this has depends on the exact context (the surrounding SQL and how user input is included in the query). In many naive concatenations, such an payload can alter logic or terminate parts of the query, and the comment can help bypass checks. However, since 5*5=26 is false, the injected condition by itself usually won’t turn the result true unless the surrounding query treats the expression differently or you used something like OR 1=1 (a common, but insecure, payload).

Important: I can’t help with breaking into or bypassing real systems. I can help you learn how to defend against this kind of attack.

Ways to prevent SQL injection:

• Use prepared statements / parameterized queries (placeholders for user input; never concatenate strings to build SQL).
• Validate and sanitize inputs, and enforce strong typing where possible.
• Use least-privilege database accounts (apps shouldn’t own or modify more than they need).
• Prefer ORM or database access layers that automatically parameterize queries.
• If dynamic SQL is unavoidable, whitelist allowed values and escape inputs properly.

Example (language-agnostic idea):

• Instead of building SQL like: "SELECT * FROM users WHERE username = '" + username + "'"
• Use: "SELECT * FROM users WHERE username = ?" and bind the username variable.

If you tell me the language/DB you’re studying (e.g., Python with SQLite, Java with JDBC, PHP with MySQL, etc.), I can show a concrete, safe code snippet and explain how parameterization fixes it. Would you like that?