Picture this: a piece of malware that slips quietly onto your systems, harvests login credentials, financial data and even cryptocurrency wallets, then discreetly ships it all to cybercriminals through a chat app. This is not science fiction — this is Predator Stealer. This information-stealing malware was first spotted in 2018 on underground hacking forums. A recent variant, written in .NET, exfiltrates stolen data through a Telegram chatbot and relies on sophisticated anti-analysis techniques. In this post we look at how Predator Stealer operates, the damage it can do, and how to detect and stop it. It is written with IT managers in mind, because they above all need to understand why this malware is so dangerous — and how to protect their organisation against it.

Anti-analysis: cleverly dodging security

Modern malware like Predator Stealer tries to evade detection with clever anti-analysis tricks. One of them is building in artificial delays via the Sleep function to outsmart sandboxes — the malware deliberately postpones its own execution, hoping automated scanners hit their time limit before any malicious behaviour begins. Predator Stealer also checks whether it is running inside a debugger or on a virtual machine. If it detects analysis tools like these, the malware can respond by posing as a harmless program, terminating immediately, or even deleting itself from disk. The stealer also looks for active processes that are tell-tale signs of a sandbox environment or security software. Together, these techniques make it harder for security researchers and automated systems to recognise and analyse the malware in time.

Stolen data: from passwords to crypto wallets

Once Predator Stealer is active, it begins a digital looting spree across all manner of sources on the infected system. The malware collects a broad range of sensitive data — practically anything of value to an attacker. That includes:

  • Browser data: Usernames and passwords, cookies, saved form data (autofill), browsing history, stored credit card details, and even crypto-wallet extensions in Chrome and Edge. With this information, attackers can gain access to online accounts or carry out financial transactions on behalf of the victim.

  • Email and VPN credentials: Saved account details for Microsoft Outlook and VPN clients are sought out. This hands attackers the keys to corporate email accounts and, potentially, access to company networks.

  • Other credentials: The malware also steals FTP passwords (for example, from FileZilla) and hunts for login details for gaming platforms and chat services such as Discord, Telegram (locally stored data) and other messengers. Even Wi-Fi network profiles (SSIDs) are read off the system.

  • Cryptocurrency wallets: Predator Stealer specifically targets crypto wallets — both references to crypto service providers and local wallet files. This lets the attacker steal the victim’s digital currency, a highly lucrative prize.

  • Files and clipboard: Files in standard folders (Desktop, Documents, Pictures, Music, Videos) are plundered, along with the contents of the clipboard. Anything recently copied — passwords, sensitive text, and so on — can leak this way.

  • System information and screenshots: Predator Stealer gathers data about the system itself (such as the public IP address, geolocation, internet provider, running processes and installed programs). It also takes screenshots of the desktop to provide a visual look into the victim’s environment. This information can help with targeted attacks or with bypassing security after the fact.

As the above shows, Predator Stealer tries to grab everything that isn’t nailed down — from personal data to business-critical information. For an IT manager, the nightmare is clear: an unauthorised party making off with your stored passwords, customer data and network access, without you ever noticing.

Exfiltration: via a Telegram bot and gofile.io

Stealing data is one thing, but getting the loot safely to the attacker matters to the malware just as much. Predator Stealer does this in an inventive and seemingly innocent way. First it packs all the collected files and information into a single ZIP archive, protected with a password (so that prying eyes — and some security scans — cannot easily inspect the contents). This archive is then uploaded to gofile.io, a free file-sharing service. Gofile.io returns a unique download link — in effect, the stolen data now sits on a publicly accessible server, ready to be retrieved.

This is where Telegram comes into the picture. Predator Stealer connects to a pre-configured Telegram bot that acts as its command-and-control channel. Through this channel, the malware forwards the freshly obtained gofile.io download link to the attacker. To the outside world it looks like ordinary chat traffic to Telegram, a service that many organisations do not block and which therefore raises less suspicion. Behind the scenes, however, that chat message means gigabytes of confidential data are waiting for the cybercriminal to collect — out of sight of traditional security measures.

Using Telegram bots for exfiltration is clever: Telegram communication is encrypted, widely accessible and hard to distinguish from legitimate traffic. Combined with the use of a public file store (such as gofile.io), this makes detecting the data theft especially challenging. For IT managers, it underlines just how creatively attackers now work to smuggle data out of your network.

Detection and prevention

The good news is that defenders are far from powerless against this advanced threat. Modern security platforms can detect and block Predator Stealer using multiple layers of protection:

  • Spotting malware on disk: As soon as Predator Stealer (or a similar malicious file) lands on a system, a next-generation antivirus engine can raise the alarm. A capable AV engine recognises the dropper file as malicious based on signatures and behaviour. Ideally, this prevents the malware from ever running in the first place.

  • Threat intelligence check: Even if the malware has not yet been explicitly flagged by antivirus, real-time threat intelligence from external feeds adds another layer. Known malware samples, IOCs (Indicators of Compromise) or suspicious characteristics of Predator Stealer can be identified against global threat intelligence feeds. In other words, if the hash or communication signature of Predator Stealer has already been seen elsewhere, the system raises the alarm straight away.

  • Behavioural detection on the endpoint: Suppose Predator Stealer runs anyway — its actions give it away. Modern Endpoint Detection & Response (EDR) watches for unusual operations. Is a process suddenly trying to read browser files containing passwords, or harvesting system information? Strong endpoint protection detects these unauthorised file operations and flags the process as suspicious. This kind of behaviour-driven detection catches the malware in the act, even when the payload is new or unknown.

In practice, these mechanisms should allow Predator Stealer to be stopped at every stage. In one controlled simulation, the malware was deliberately allowed to run its full course (detection only, no blocking) to see what alerts it would trigger. The result was clear: every stage — from dropping the file to collecting data and attempting exfiltration — was picked up by at least one security mechanism. With prevention mode enabled, Predator Stealer would therefore be neutralised at the very first violation. For you as an IT manager, the lesson is that a layered security strategy is essential: combine traditional antivirus with behavioural analysis and threat intelligence, so that both known and unknown threats are stopped in time.

Conclusion

Predator Stealer is a wake-up call for anyone responsible for IT security. This malware shows just how refined cybercriminals have become: from anti-sandbox tricks to abusing everyday services like Telegram and gofile.io to spirit data away. The potential impact is enormous — confidential business information, customer data, financial details and passwords are all up for grabs when this infostealer strikes.

For IT managers, the takeaway is clear: be proactive. Make sure you have up-to-date endpoint security that recognises not only known malware signatures but also unusual behaviour. Monitor outbound traffic for unusual patterns — for example, unknown uploads or unauthorised communication to services like Telegram. And have an incident response plan ready for the moment something does slip through. It is also worth validating those defences in practice: a regular penetration test helps confirm that your detection and response actually hold up against techniques like these.

By staying alert and making use of modern security tools, we can keep one step ahead of malware like Predator Stealer. This new variant may be cunning, but with the right approach we turn the hunter into the hunted.

Disclaimer: This blog post is based on the analysis “CyOps Analysis: Predator Stealer” by the Cynet team. See Cynet’s original post for the full report and all the details.

Worried that an infostealer like Predator Stealer could slip past your current defences? Rootsec can help you detect, contain and stop it. Book a free consultation.