How to Find Files Newer Than a Specific File in Ubuntu (find -newer)

The Relative Time Audit

In Ubuntu Linux, system administrators frequently need to perform timeline forensics. If you know exactly when a server breach occurred (for example, the exact timestamp of a corrupted log file), you need to find every single file that was modified after that specific event. Instead of calculating complex hour deltas with -mtime or -mmin, you can use the corrupted file itself as a temporal anchor. You must instruct the search engine to use that file’s exact modification timestamp as the baseline for the search.

Using the find Command with -newer

The Linux find command utilizes the -newer flag to exclusively search for files that were modified more recently than a specific reference file.

1. Open your Terminal application (Ctrl + Alt + T) or log into your server via SSH.
2. To search the /var/www/ directory for any file modified after a file named corrupted_index.php, type the following command exactly:
3. find /var/www/ -newer /var/www/corrupted_index.php
4. Press Enter.

Temporal Forensics

The syntax requires you to provide the absolute or relative path to the anchor file immediately after the -newer flag. The find binary will read the exact modification timestamp of corrupted_index.php (down to the nanosecond) and then scan the target directory, returning only files whose timestamps are mathematically greater (newer) than the anchor. This allows you to instantly isolate every script, payload, or configuration change uploaded by an attacker immediately following the initial compromise.