File Integrity: What Did AIDE Flag?

AIDE (a file-integrity monitor) ran its check and reported differences since the last baseline. The report is at /root/aide-report.txt (it differs per session). It lists an added file, a removed file and two CHANGED files. One changed file is a log that changes every day, which is expected. The other is a CRITICAL system file that attackers love editing (to add accounts, grant sudo, plant keys or persist). Identify that critical changed file and record its full path to /root/answers/changed_file.txt.