Confirming Credit Card Leaks: Log Analysis for Security Analysts

C.

The correct answer is C.

Explanation:

The analyst is searching for potential credit card leaks in a log file that stores all data in hexadecimal format. The analyst needs to convert the hexadecimal format to readable text format before searching for the credit card number. The command "xxd" can be used to convert hexadecimal to readable text format, and "egrep" can be used to search for patterns in the text.

Option A: cat log |xxd "r "p | egrep "v [0-9]{16}' This command has an error in it. The option "r" in the xxd command is not correct. The correct option is "-r". Also, the regex pattern in the egrep command is not correct. The regex pattern should be "\b[0-9a-fA-F]{16}\b" to match a valid credit card number in hexadecimal format.

Option B: egrep (3[0-9]){16}' log This command searches for 16 digits in a row that start with a number 3 in the log file. However, credit card numbers can start with any number between 1 and 5, so this command may not detect all credit card numbers.

Option C: cat log |xxd "r "p | egrep [0-9]{16}' This command uses the correct xxd and egrep commands. The xxd command converts the hexadecimal format to readable text format, and the egrep command searches for 16 consecutive digits in the text format. The regex pattern used is "[0-9]{16}", which matches any sequence of 16 digits.

Option D: egrep [0-9]{16}' log |xxd This command is incorrect because it first searches for a pattern in the log file and then tries to convert the output to hexadecimal format using the xxd command. This command will not work because egrep outputs text, and xxd expects hexadecimal input.

In summary, option C is the correct answer as it uses the correct commands to search for potential credit card leaks in a hexadecimal format log file.