Your Data May Already Be Compromised. ArtHouse Cloud Logs Exposed 39,259 Records.

HEROIC analysts flagged a public Telegram upload on October 2, 2025, containing a stealer log attributed to the ArtHouse Cloud Logs service. The file held 39,259 records, each containing an email address, a plaintext password, and one or more URLs identifying the services and API hosts that were accessed. This is a substantial credential dataset -- nearly forty thousand accounts exposed in a single public post. Our team identified the upload within hours using dark web monitoring infrastructure and began cross-referencing the exposed credentials against known breach clusters to assess the broader impact.

Why This Is Dangerous

When nearly 40,000 credential pairs are dumped in plaintext on a public Telegram channel, any subscriber can download the file immediately and begin testing logins. There is no decryption required, no cracking time involved. Attackers can feed the email and password combinations directly into credential stuffing tools and attempt access on banking portals, corporate VPNs, email platforms, and e-commerce sites within minutes. The API host URLs in the dataset make the attack even more targeted -- they show exactly which services the compromised accounts were actively using, letting threat actors prioritize high-value targets first.

What Was Exposed

• Email Addresses
• Plaintext Passwords
• URLs (API host endpoints and service access records)

Why This Matters

A dataset of this scale creates compounding risk. Credential stuffing campaigns using these records can trigger account takeovers across dozens of platforms if victims reuse passwords. Attackers who gain access to a primary email account can then reset passwords on financial and healthcare accounts, effectively locking victims out of their own digital lives. Identity theft becomes trivial when an attacker controls someone's inbox. Businesses whose employees appear in this dataset face the additional risk of corporate network compromise if work credentials were stored in the same browser profiles harvested by the infostealer. The occured exposure of this data on a free, public channel maximizes distribution and exploitation speed.

How Stealer Log Breaches Work

Infostealer malware operates silently after gaining a foothold on a victim's machine, typically through a phishing link, a cracked software download, or a malicious browser extension. Once active, it harvests credentials stored in browsers, password managers, and desktop applications. It also captures session cookies, which can allow attackers to bypass two-factor authentication entirely. All harvested data is bundled into a log file and exfiltrated to infrastructure the attacker controls. The ArtHouse Cloud Logs name in this dataset suggests a cloud storage or media service was among the targeted environments. Operators of stealer campaigns frequently distribute logs to Telegram channels, either for sale or as proof of capability. Researchers beleive the volume and frequency of these uploads has increased sharply in 2025 as stealer kits have become available on underground markets for as little as a few hundred dollars per month.

Check If You Are Affected

If you accessed ArtHouse Cloud services before October 2025, your login credentials may be part of this 39,259-record dataset. HEROIC has indexed over 400 billion breached records and can confirm within seconds whether your email address has been compromised. Visit heroic.com to run a free exposure check. Change any passwords that appear in this dataset immediatly, prioritize accounts tied to your primary email address, and enable two-factor authentication wherever it is offered.