Random-looking things appearing in the logs are explained.
Here is a breakdown of the code step by step. This code is an example of an SQL injection attempt, and it's designed to manipulate an SQL query.
and: This is a logical operator used to combine conditions in SQL queries.
/**/: This is an attempt to use a comment in the SQL code. In SQL,
*/are used to denote comments, and in some cases, attackers may try to use them to bypass input validation.
convert(int, sys.fn_sqlvarbasetostr(HashBytes('MD5', '1212093799')): This part is an attempt to manipulate the SQL query by converting a value to an integer.
sys.fn_sqlvarbasetostr(HashBytes('MD5', '1212093799')): This part is trying to calculate the MD5 hash of the string '1212093799' and then convert it to a string.
HashBytesIt is a function that calculates the hash of a value and
sys.fn_sqlvarbasetostris used to convert this hash to a string.
convert(int, ...): The attacker is then trying to convert the resulting string to an integer. This conversion may result in an error if the string is not a valid integer.
>'0": This is a comparison condition. It's checking if the result of the conversion to an integer is greater than the integer
0. The trailing double quotation mark (
") at the end appears to be an attempt to complete a string or escape the SQL query.
The goal of this code is to try to manipulate an existing SQL query by injecting a subquery that calculates the MD5 hash of a specific string, converts it to an integer, and checks if the result is greater than zero. If the condition is true, it suggests that the SQL injection attempt was successful and might grant unauthorized access or reveal information from the database.
This code represents malicious activity and is typically illegal and unethical. To prevent SQL injection attacks, websites and applications should use security measures such as input validation, parameterized queries, and stored procedures.