• Posted by: Eng. Donya Bino
• December 04, 2025

How Hackers Use Public Information (OSINT) to Target People

If you’ve ever wondered how hackers know so much about their targets, here’s the uncomfortably simple answer: we give them the information. Not directly, of coursenno one posts “Here’s everything you need to hack me” on social media. But the bits and pieces we share over the years add up. And attackers are very good at connecting those pieces.

When they run an OSINT sweep, they aren’t hunting for secret files. They’re sifting through public breadcrumbs. Old posts. Forgotten PDFs. Profiles you haven’t updated since your first job. Anything that tells them who you are, what you do, and how you operate.

Here’s the kind of information they quietly collect:
Identity Details
1. Names, emails, phone numbers
2. Job titles, company structure, org charts
3. Reused usernames across different platforms
Every detail helps attackers shape their first message so it feels familiar.

Daily Patterns
1. Work hours revealed through online activity
2. Travel plans posted a little too early
3. Weekend habits from photos and check-ins
Knowing when you’re busy or away makes timing easier.

Technical Clues Hidden in Plain Sight
1. Metadata from photos and documents
2. Email headers that leak server info
3. GitHub commits showing internal paths
These tiny hints help attackers craft attacks that look “inside the company.”

Relationships and Social Circles
1. Coworkers, teams, and direct managers
2. Vendors you work with
3. People you tag often
Attackers use these connections to make their messages sound trustworthy.

Accidental Data in Public Files
1. Slide decks with internal links
2. PDFs with revision histories
3. Job postings that reveal the tech stack
These are quiet goldmines for targeted attacks.

The worrying part is how ordinary all of this is. None of it requires hacking skills. It’s just patient collection. By the time an attacker reaches out, they already know what department you’re in, the tools you use, and sometimes even the tone you write in. That’s why well-crafted phishing works so well, it fits the story they built from your public trail.

Reducing exposure is far easier than people think:
1. Clean up old profiles and remove outdated details.
2. Check metadata before posting documents or images.
3. Keep personal travel plans private until after the trip.
4. Limit what you share about workplace tools and projects.
5. Review privacy settings a few times a year.

A smaller digital footprint doesn’t make you invisible, but it forces attackers to work harder. And most of them move on when things aren’t easy.