MailAccess Combos 4 Leak: 2,900 Accounts Ripe for Takeover

HEROIC analysts have flagged a stealer log collection titled MailAccess Combos 4 that was uploaded to a public Telegram channel in June 2026. The dataset contains 2,900 records, each consisting of an email address, a plaintext password, and the URL of the service where the credentials were captured. The sequential numbering in the file name — "Combos 4" — indicates this is part of a recurring series, suggesting an active and ongoing credential harvesting operation that regularly produces new batches of stolen email access data.

Every record in this collection represents an email account that is ripe for unauthorized access. The credentials are plaintext, the data is fresh, and the file is freely available to anyone on Telegram.

Why Plaintext Passwords Make These Accounts Defenseless

The 2,900 passwords in MailAccess Combos 4 are stored without any form of encryption or hashing. They appear exactly as victims typed them, which means there is no technical challenge standing between an attacker and a successful login. The credentials are weaponized the instant they are downloaded.

For email accounts, this vulnerability is especially critical. Email is the backbone of digital identity — the single point through which password resets, account verifications, and sensitive communications flow. An attacker who takes over an email account effectively takes control of the victim's entire online identity.

The fact that this is the fourth installment in a series amplifies the concern. Previous volumes may have already been exploited, and threat actors who found value in earlier releases will be primed to act quickly on this latest batch.

What Was Exposed in the MailAccess Combos 4 Dump

• Email Addresses — A curated collection of email accounts selected specifically for their mail access potential, making this dump a premium resource for attackers focused on inbox compromise and downstream account takeovers.
• Plaintext Passwords — Completely unencrypted credentials captured from infected devices, ready for immediate use in login attempts without any preprocessing.
• URLs — The specific login pages and web services where each credential pair was captured, providing attackers with a verified list of active services tied to each victim's email account.

Why a Numbered Series Means Escalating Risk

The "4" in MailAccess Combos 4 tells an important story. This is not an isolated incident but part of a systematic operation that has already produced at least three prior credential dumps. Each installment feeds fresh data into the underground credential economy, and the existence of a series means the operation behind it is established, productive, and ongoing.

For the 2,900 individuals in this particular batch, the timing matters. Fresh credential dumps command the highest prices and receive the most immediate attention from threat actors because the passwords are most likely to still be active. Attackers race to exploit new uploads before victims have a chance to change their credentials.

The cumulative impact across all volumes in this series likely extends to tens of thousands of compromised email accounts. Each new release adds fuel to credential stuffing campaigns and expands the pool of exploitable accounts available to the cybercriminal community.

How Stealer Logs Supply a Steady Stream of Stolen Credentials

The recurring nature of the MailAccess Combos series reflects the industrial efficiency of modern infostealer operations. Malware campaigns continuously infect new devices through phishing, malvertising, and trojanized software. Each infected device yields a fresh batch of credentials that operators collect, sort, and package for distribution.

The sorting process is what produces focused collections like MailAccess Combos. Operators filter raw stealer logs to isolate email credentials — the most valuable subset for account takeover operations — and release them in numbered batches to build a following among buyers and downloaders.

Telegram serves as the primary storefront for these operations. Channels build subscriber bases by releasing regular, numbered uploads that create anticipation and repeat engagement. The MailAccess Combos series likely has a dedicated audience of threat actors who download each new installment as soon as it appears.

Check If Your Credentials Appear in This Leak

If your email account was compromised by infostealer malware at any point, your credentials could appear in MailAccess Combos 4 or in any other volume of this series. The ongoing nature of this operation means new victims are added with each release.

HEROIC offers a free breach scanner that checks your email address against more than 400 billion records from known breaches and stealer log distributions worldwide. Search now to determine if your credentials have been exposed. If a match is found, change your email password immediately, review your account for unauthorized logins or forwarding rules, and enable two-factor authentication to block future unauthorized access attempts.