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How Do Hackers Steal Passwords?

A password is like a house key. If someone copies your key, watches you type your door code, or just guesses it because it's "1234" — they're in, no breaking required.

Guessing Games

Not every password theft involves malware or a convincing fake page at all — sometimes it's simpler than that. Hackers keep enormous, constantly updated lists of the most common real-world passwords: "password123," birthdays, pet names, keyboard patterns like "qwerty," and every password that's ever shown up in a previous breach. These lists get tried automatically, over and over, against huge numbers of accounts at once — not because it's clever, but because it's cheap to run and a surprising number of people still use passwords simple enough to be on the list.

Phishing Pages

Hackers build fake login pages that look exactly like the real thing — the same logo, the same layout, sometimes even the same URL misspelled by a single character you'd never notice at a glance. You type your password thinking you're logging into your bank, your email, your workplace — but you just handed your key to a stranger, and the fake page usually redirects you to the real site afterward so nothing feels wrong. The most convincing versions even mimic multi-factor prompts in real time, relaying your one-time code the moment you enter it.

Silent Software That Watches Everything

The bigger, quieter threat in 2025 isn't a fake login page at all — it's software called an infostealer, which secretly harvests every saved password sitting in your browser, along with autofill data, cryptocurrency wallets, and the login cookies that let websites recognize you without a password at all. It usually arrives through a phishing email, a malicious ad, or a "free" download of cracked software, and once it's running, the theft is over in seconds — often before the person whose computer it's on notices anything happened at all.

The scale of this specific threat has genuinely exploded. Threat intelligence firm Flashpoint reported that infostealers stole more than 1.8 billion credentials in 2025 alone, pulled from 5.8 million infected devices.1 Security firm Specops separately found that malware-stolen password volume hit roughly 6 billion in 2025 — about six times the volume recorded the year before.2 Neither of those numbers is a typo. This isn't a niche technique anymore; according to one 2025 stealer-log analysis, stolen passwords and cookies now show up in 86% of all breaches.

Malware-Stolen Passwords, Year Over Year
Temporal — global password volume harvested by infostealer malware
In more technical terms
Infostealer
Malware built specifically to silently harvest saved credentials, session cookies, autofill data, and crypto wallet files from an infected device, then exfiltrate them to an attacker-controlled server.
Stealer log
The packaged output of an infostealer infection — everything harvested from one device, bundled together and sold on dark web markets, often for as little as a few dollars.
Combolist
A structured file of email-and-password pairs compiled from breaches and stealer logs, used to automate credential stuffing attacks against many accounts at once.
Malware-as-a-Service (MaaS)
Infostealer tools rented out as a subscription — putting industrial-scale credential theft within reach of attackers with no coding ability at all.

A Small Number of Tools Doing Most of the Damage

Despite the sheer volume, this isn't hundreds of different pieces of malware each doing a little damage — it's a small handful of dominant families doing almost all of it. Two infostealer families in particular, LummaC2 and RedLine, are together responsible for nearly 90% of attributed stealer-log credential theft.3 That concentration matters practically: security teams and antivirus vendors that specifically detect and block these two families are covering the overwhelming majority of real-world risk, not just a small slice of it.

Where Stolen-Credential Logs Actually Come From
Part-to-whole — share of attributed stealer-log credential theft

Data Breaches and Password Reuse

When a company gets hacked, huge lists of usernames and passwords sometimes leak onto the internet — and get folded straight into those same dark-web credential databases. If you reuse the same password everywhere, one leak anywhere can unlock every account tied to it, because attackers don't need to guess anything; they just try the leaked pair against every major website and see where it also works. This is called credential stuffing, and it's now the single most common way real breaches start.

Research into infostealer-infected users found the median person had only about 49% distinct passwords across all their accounts — meaning roughly half of everything they'd saved was reused or repeated somewhere.4 For someone with 80 online accounts following that pattern, that's around 40 passwords doing double or triple duty, and a single infected device can expose the login for nearly all of them at once, not just one.

Password Reuse Among Infected Users
Comparison — share of saved passwords that are unique vs. reused
Source: Verizon DBIR-related infostealer research, cited via dualmedia.com, 2025

What This Actually Means for You

None of these theft methods require the hacker to "break" anything technical — they rely on a password being reusable, a login page being convincing, or a piece of quiet malware nobody noticed. A few practical takeaways:

Sources
  1. Flashpoint infostealer research, 2025, cited via shattered.io
  2. Specops / Stingrai malware-password volume analysis, 2026 — cyberfenceplatform.com
  3. Stealer-log attribution data, cited via cyberfenceplatform.com, 2026
  4. Infostealer-infected user password-uniqueness research, cited via dualmedia.com, 2025

This is why every account on NUURBY requires a real password (not a shared key) and why we hash passwords so even we can't see yours in plain text.