Inside the Stealer Log Gold Rush: How Credential Theft Became the Cybercrime Industry’s Billion-Row Engine

In today’s cybercrime economy, few assets are as lucrative or as scalable as the humble stealer log.

Born from infections by lightweight infostealer malware, these files are now the backbone of a sprawling underground market that thrives on hijacked credentials, browser cookies, and crypto wallet keys. Once dismissed as commodity threats, stealer logs are now driving ransomware attacks, identity fraud, and full-scale corporate breaches at an industrial scale.

According to Verizon’s 2025 Data Breach Investigations Report, over half of ransomware victims had their domains exposed in stealer log marketplaces prior to being compromised. That correlation isn’t just statistical noise—it’s the new normal. IBM’s research backs it up, reporting an 84% surge in phishing campaigns delivering infostealers in the past year. Among the top players in this malware class: Lumma, Vidar, RedLine, RisePro, and Stealc.

“Credential theft isn’t the side gig anymore—it’s the main job,” said Selçuk Gökalp, CEO of SOCRadar. “Stealer logs give threat actors everything they need to bypass security controls, including multi-factor authentication. This is how they log in like insiders.”

What’s in a Log?

Each stealer log is a snapshot of a compromised system: browser autofill data, saved passwords, session tokens, IP addresses, device specs, and sometimes even cryptocurrency private keys. Structured in searchable formats like JSON or TXT, these logs are designed for criminal efficiency. Attackers can simply search for terms like “admin,” “vpn,” or “bank” to isolate high-value targets.

Far from being isolated incidents, infostealer infections are now part of a decentralized data harvesting pipeline. The malware quietly infiltrates systems via phishing or software downloads, siphons data to a command-and-control server, and that data is soon packaged, sold, and often weaponized within days.

Anatomy of an Exploit Chain

One log can unravel an entire enterprise. Just ask Uber. In 2022, an attacker leveraged credentials obtained from Racoon and Vidar stealer logs, triggering MFA fatigue to access internal systems and leak vulnerability reports. MGM and Caesars followed in 2023, compromised through help desk impersonation and stealer-sourced Okta credentials.

The trend has only intensified. In 2024, threat actor ShinyHunters used long-exposed credentials from Snowflake customer accounts to orchestrate massive data thefts. And in 2025, Telefónica suffered a breach rooted in credentials extracted from over 500 employees, harvested months earlier through infostealer infections.

The raw materials? Not 0-days. Not insider backdoors. Just logs.

MFA Isn’t Bulletproof—Cookies Are the Culprit

A recurring theme in these breaches: attackers sidestepping MFA entirely by importing session cookies into their browsers. This method mirrors Adversary-in-the-Middle attacks but requires no real-time interception. Just a cookie file pulled from a victim’s Chrome profile and a replayed session.

The Okta incident in 2023 drove this home. An employee’s personal Gmail account, accessed from a work laptop, led to credential exposure via a Chrome-stored password. That enabled malware installation and, eventually, unauthorized access to Okta’s support system—via stolen cookies embedded in HAR files.

Marketplaces, Bots, and Telegrams

These logs don’t sit idle. They're traded across underground forums like Exploit and XSS, encrypted Telegram groups like Moon Cloud, and marketplaces like Russian Market or the now-defunct Genesis Market.

Some are auctioned to the highest bidder. Others are dumped for free—part brag, part revenge, part brand-building.

Pricing models vary. Bulk logs go cheap. Handpicked entries tied to financial institutions or cloud admin portals fetch hundreds. Monthly subscriptions offer tiered access to fresh logs from active malware operators.

“It’s no longer just the dark web. These trades are happening in semi-public chat channels with automation bots and loyalty programs,” said Gökalp. “This is cybercrime, SaaS-style.”

When Data Lives Forever

Even years-old credentials pose a risk. In 2025, a breach of Samsung Germany’s ticketing vendor traced back to a Raccoon Stealer infection from 2021. Similarly, Orange Spain’s 2024 BGP hijack relied on credentials stolen months earlier from RIPE NCC accounts.

And there’s volume. The ALIEN TXTBASE leak in 2024 spilled over 23 billion rows of stealer-collected records into the wild. Analysis showed that nearly 9% of victims came from Brazil, with India and Indonesia following closely—markets where cybersecurity controls lag behind digital adoption.

Stealer Logs as a Ransomware Catalyst

Verizon found that 54% of ransomware victims had their credentials exposed in stealer logs before the attack. In many cases, credentials appeared in black markets days—or even weeks—before extortion notes were dropped. Nearly half of those incidents involved compromised corporate email accounts, often used for initial access or reconnaissance.

These aren’t isolated cases. They’re evidence of an exploit model where malware, credentials, and ransomware are tightly interlinked.

Fighting Back: What Actually Works?

SOCRadar and others advocate for a mix of external monitoring and internal hardening:

• Dark Web Surveillance: Continuous scanning of underground marketplaces to flag exposed assets.

  
  

• Session Replay Detection: Flagging cookie reuse from unexpected geolocations or devices.

  
  

• Credential Hygiene Enforcement: Strong password policies and frequent rotation across both managed and BYOD devices.

• Deception Techniques: Honeypots, decoy credentials, and behavioral anomaly detection.

  
  

• CTI Platform Integration: Automating threat intel into response workflows to catch leaks early.

  
  

The Bottom Line

Stealer logs are no longer a side effect of broader threats—they are the threat. As access becomes more valuable than zero-days, attackers are increasingly logging in instead of breaking in. And unless organizations start treating credential theft with the same urgency as traditional breaches, they’ll keep finding themselves on the wrong end of a quietly stolen login.

“You can patch software,” Gökalp said. “But you can’t patch a stolen identity.”