CrashStealer, a new macOS information-stealing malware named for Apple's Mac operating system, bypasses built-in security protections by using an Apple notarized application, demonstrating a growing trend of malicious actors utilizing legitimate software verification mechanisms in order to target Apple users.
Jamf Threat Labs researchers discovered that the malware is distributed via a disk image named Werkbit.app that is signed and notarized by Apple. Due to the fact that the installer is notarized by Apple and has a valid developer ID, Gatekeeper security checks can be successfully passed by the installer, increasing user confidence and acceptance of the application.
In early May 2026, Jamf Threat Labs identified CrashStealer as a suspicious macOS sample uploaded to VirusTotal. Activated infections were detected by researchers in early July, indicating the malware had progressed from development to real-world deployment.
Based on the timeline, the operators seem to have refined the malware before launching broader attacks on macOS. This macOS stealer is written in native C++, unlike many macOS stealers, which rely on AppleScript or Objective-C wrappers. As a result, CrashStealer is more difficult to analyze while ensuring enhanced performance. Researchers have reported that the malware validates the user's macOS login password.
Once the password has been validated, the malware can unlock the user's login keychain and gain access to additional sensitive information. The attack chain is designed to keep the user's identity hidden. A GitHub repository is utilized by the malware to retrieve configuration data after the victim launches the installer, which is then used to download the final malicious payload.
GitHub-hosted configurations contain instructions for downloading shell scripts that are responsible for retrieving the final malware payload from attacker-controlled infrastructure when the victim launches the installer. CrashStealer reduces its forensic footprint by decoding its contents during execution rather than storing them in plain text during execution.
The CrashStealer application establishes persistence as a LaunchAgent, utilizes multiple anti-analysis techniques, and checks for installed security or forensic tools before harvesting data by employing multiple anti-analysis techniques. As a precaution, the malware masquerades as CrashReporter, Apple's legitimate crash reporting utility.
By using Apple's bundle identifier, icon, and naming conventions, the malware makes malicious activity appear to be similar to legitimate system activity. This malware targets credentials stored in Chromium-based browsers as well as Mozilla Firefox, resulting in a significant increase in browsers affected. MetaMask, Phantom, Coinbase Wallet, Trust Wallet, Rabby, OKX Wallet, Exodus, Keplr, Solflare, Backpack, and MetaMask are among the many cryptocurrency wallet extensions that search for data.
As part of the attack, CrashStealer attempts to extract information from 14 password managers, including 1Password, Bitwarden, LastPass, Dashlane, Keeper, KeePassXC, NordPass, Enpass, and RoboForm. In addition to collecting files from the user's Documents and Downloads folder, the malware compresses the data into a ZIP archive to reduce the possibility of interception.
To protect the collected data, it is encrypted using AES-GCM before being transmitted via libcurl to an attacker-controlled server. CrashStealer is noted by researchers as encrypting each file before exfiltration, rather than protecting the entire archive. As a result of its use of industry-standard cryptographic techniques, the malware makes intercepted data significantly more difficult for defenders to analyze without the appropriate key to decrypt.
Researchers at Jamf observed that the malware incorporates code obfuscation, encrypted strings, control-flow flattening, and layered anti-debugging techniques into its data exfiltration mechanism, making it significantly more resilient than typical information commodity thieves.
Investigators also discovered additional domains and operator infrastructure linked to the campaign, including a password-protected management panel that is believed to be used by the attackers. It has been demonstrated that CrashStealer is not a standalone malware sample, but is part of a coordinated operation.
Researchers believe CrashStealer exemplifies a growing trend in macOS malware, demonstrating the combination of trusted software signing, multiple stages of delivery, sophisticated anti-analysis techniques, and strong encryption to make it more difficult to detect. Furthermore, the campaign emphasizes the growing tendency of attackers to exploit legitimate Apple security mechanisms for malicious delivery, reinforcing the need for users to verify software sources even when applications pass Gatekeeper checks.
In CrashStealer, cybercriminals demonstrate the increasing use of trusted security mechanisms to avoid detection and compromise macOS systems by exploiting trusted security mechanisms to evade detection. Increasingly sophisticated methods of delivery and stronger encryption are being adopted by attackers; therefore, organizations and users need to remain vigilant by ensuring that they download software only from trusted sources, monitoring unusual activity, and updating their security solutions.
