PamStealer macOS infostealer impersonates Maccy and verifies login passwords via PAM

New PamStealer macOS Malware Uses Clever Tradecraft To Remain Stealthy

An anonymous reader quotes a report from Ars Technica: Researchers have found a never-before-seen piece of macOS malware that combines a series of clever tradecraft to infect Macs with stealthy, custom-developed credential-stealing code. The malware is delivered in two stages. The first is distributed in a disk image that masquerades as Maccy, a clipboard manager for Macs. It's compiled as AppleScript that is notable for the way it delivers the second stage. The malware is named PamStealer because the Rust-written infostealer uses the Pluggable Authentication Modules interface built into macOS to validate the target's login password before sending it to an attacker-controlled server. [...] PamStealer shows a native password prompt designed to resemble a system authorization request. Text that appears with the prompt says: "Maccy wants to make changes. Enter your password to allow this." As noted earlier, once a target complies, the malware validates it locally through the PAM API. "This check is done entirely through PAM: there is no call out to dscl, security, osascript or any spawned process to verify the password, as many commodity macOS stealers do," [said Jamf, a security firm for macOS users]. "The result is a quieter routine that keeps only a verified password, and one fewer process chain for defenders to detect on." If the validation fails, PamStealer displays the prompts again until it receives the correct one. Once the target enters the correct password, PamStealer displays a message stating that the file is damaged and can't be installed. This is designed to be a decoy to prevent the target from suspecting anything is amiss. The malware uses tactics to maximize the information it can steal. One tactic is to request the target grant full disk access to the fake Maccy app. It also contains code designed to access ethereum accounts. The various techniques -- particularly the Script Editor lure, a self-contained JXA dropper, a Rust-based second stage, and local validation of credentials through PAM are all noteworthy. Read more of this story at Slashdot.

8 hours ago

PamStealer Uses Fake Maccy Sites and PAM Checks to Steal Mac Login Passwords

Cybersecurity researchers have flagged a new macOS information stealer called PamStealer that employs a series of clever tricks to infect systems and siphon sensitive data. The stealer, discovered by Jamf Threat Labs, is distributed as a compiled AppleScript (.scpt) file impersonating Maccy, a legitimate open-source clipboard manager. It has been codenamed PamStealer owing to its ability to

15 hours ago

New Mac infostealer confirms stolen passwords before stealing data

A newly discovered macOS infostealer verifies Mac login passwords before stealing sensitive data, giving attackers immediate confirmation that compromised credentials will actually work.PamStealerResearchers at Jamf Threat Labs have documented a new macOS malware campaign built around an infostealer called PamStealer. PamStealer disguises itself as the Maccy clipboard manager and uses AppleScript alongside a Rust payload to infect Macs.Jamf found that PamStealer verifies login passwords through Apple's Pluggable Authentication Modules before stealing additional data. Password verification sets PamStealer apart from most macOS infostealers, which typically capture whatever password a victim enters without confirming that it's valid.The campaign begins with a fake website that closely imitates the legitimate Maccy clipboard manager. Next, the fake website delivers a malicious AppleScript application disguised as Maccy. Continue Reading on AppleInsider | Discuss on our Forums

1 day ago