The klaus_cloud_public 748logs Breach Happened in 2023. The Data Just Went Public on Telegram.

HEROIC analysts detected the "klaus_cloud_public 748logs" stealer log file on a public Telegram channel on November 4, 2023. The file exposed 8,408 records taken directly from infected endpoints, each containing an email address, a plaintext password, and URLs for services and API hosts the compromised device had accessed. The label "748logs" indicates this package was assembled from 748 seperate infection logs before being uploaded as a single public file -- meaning the data spans a broad range of individuals and services, not a single company or platform.

Why This Is Dangerous

With 8,408 plaintext passwords available in a single publicly shared file, this breach gives attackers an immediate toolkit for account takeover. Unlike hashed passwords, plaintext credentials require no cracking -- they can be used the moment the file is downloaded. The presence of API host URLs alongside these passwords also means attackers may be able to access backend services, developer environments, and business tools, not just personal accounts. Once a file like this lands on Telegram, it can be downloaded and put to use by thousands of people within hours. Victims have no way of knowing their credentials were recieved by attackers unless they actively check.

What Was Exposed

• Email Addresses
• Plaintext Passwords
• URLs (including API hosts and service login pages from infected devices)

Why This Matters

Large aggregated stealer logs like this one are among the most valuable datasets on dark web markets because they cover so many different services at once. Credential stuffing attacks fuelled by logs this size can run continously for months, testing email and password combinations across banking sites, email providers, e-commerce platforms, and more. Account takeover, identity theft, and financial fraud are the most likely outcomes for anyone whose data appears in this file. Victims typically do not recieve any notification -- they find out only after the damage is done. Checking your email against a breach database is one of the few ways to get ahead of an attack before it occures.

How Stealer Log Breaches Work

Info-stealer malware silently infects devices through phishing emails, fake software downloads, and malicious browser extensions. Once installed, it copies all passwords saved in the browser, records session cookies, and logs every site visited. This information is packaged into a log file and transmitted to the attacker's server. The attacker then aggregates logs from many infected machines -- in this case 748 individual logs -- and uploads the combined file to Telegram for distribution. The "klaus_cloud_public" label suggests the data may have been staged in a cloud environment before being released publicly. The entire process can happen without the victim ever suspecting anything is wrong.

Check If You Are Affected

HEROIC's free scanner checks your email address against more than 400 billion exposed records, including the full klaus_cloud_public 748logs dataset and thousands of other stealer logs and data breach compilations. If your credentials appear in this breach or any other known leak, you will receive an instant alert so you can change your passwords and secure your accounts before an attacker does. Run a free scan at HEROIC right now.