Inside Logs_20 December: How Infostealer Malware Stole 13,185 Passwords

HEROIC analysts identified a stealer log file posted to a public Telegram channel on December 20, 2024, attributed to a source labeled Logs_20 December. The file contained 13,185 records harvested from infected endpoints across the United States. Each record included the victim's email address, their plaintext password, and the URL of the site or service where those credentials were active. The raw, unencrypted nature of the password data means these credentials could be weaponized immediately upon download, with no cracking or decryption required. HEROIC analysts flagged this dataset as high priority due to the volume and the direct usability of the exposed information.

Why This Is Dangerous

A file with 13,185 sets of live credentials and matching site URLs is not passive data -- it is a loaded attack kit. Anyone who downloaded this log from Telegram could begin attempting logins at every URL in the file within minutes. The plaintext passwords remove the single biggest technical barrier to account takeover. Beyond the sites listed in the log, many users reuse passwords, so these credentials may also unlock email accounts, banking apps, cloud storage, and social media profiles that were never part of the original infection. The scale here means thousands of individuals face real and immediate risk from account hijacking, data theft, and financial fraud.

What Was Exposed in the Logs_20 December Stealer Log

• Email Addresses -- Active email addresses linked to real user accounts and services
• Plaintext Passwords -- Unencrypted passwords captured directly from infected devices
• URLs -- The specific websites and API endpoints associated with each credential pair

Why This Matters for Anyone Whose Data Was Captured

Credential stuffing attacks using logs like this one are one of the most common causes of account takeover today. Attackers feed the email and password pairs into automated tools that try them across dozens of popular platforms at once. Banking portals, email providers, subscription services, and e-commerce sites all become targets. Once an attacker is inside an email account, they can use password reset functions to take over other accounts the victim holds, compounding the damage far beyond what the original log contained. Identity theft and financial fraud are definately realistic outcomes for people whose data appears in this file. Victims often have no idea their accounts have been accessed until significant damage is already done.

Inside Infostealer Malware: How the Logs_20 December Data Was Harvested

Infostealer malware is designed from the ground up to collect credentials silently. It typically reaches a device through one of a few common vectors: a phishing email with a malicious attachment, a fake software installer downloaded from a third-party site, or a drive-by download triggered by visiting a compromised webpage. Once running, the malware monitors browser activity and harvests saved passwords stored locally by Chrome, Firefox, Edge, and other browsers. It logs keystrokes on login pages and captures session cookies that can be used to authenticate without even entering a password. Every piece of data it collects gets written into a structured log file. That file is then transmitted back to the attacker's infrastructure. The attacker organizes these logs and shares or sells them, often on Telegram channels with thousands of subscribers. The Logs_20 December file is a textbook example of this process: malware infected devices, captured credentials from real users, and the resulting log ended up publicly available within days. Understanding this attack chain helps explain why endpoint security and avoiding untrusted downloads are the most effective defenses.

Check If You Are Affected by the Logs_20 December Breach

If your email address was active on any US-based service in late 2024, there is a chance your credentials could appear in this dataset. HEROIC offers a completely free breach scanner at heroic.com that searches a database of more than 400 billion exposed records, including stealer logs like this one. It is among the most comprehensive breach databases avaliable to the public. Type in your email address and get an instant result -- no account, no payment, no catch. If your data appears, change your passwords immediately, especially for email and any financial accounts. Enabling two-factor authentication on your most important accounts is the next most effective step you can take.