A harmful computer virus called StealC has recently been updated. It is now harder to detect and better at stealing personal data from users. This malware has been around for a few years, but its latest version makes it even more of a threat.
What is StealC?
StealC is a type of malicious software known as an "info-stealer." It is designed to sneak into your computer, steal personal data like saved passwords and cookies, and even help other harmful programs get inside. It became popular on hacker forums in 2023, with access sold for about $200 per month.
In 2024, it was widely used in fake online ads. Some attacks locked devices into a mode where users could not do anything except follow the attacker's instructions. This showed how advanced and harmful StealC could be.
Later that year, it was discovered that the malware could get around new security features in Google Chrome. These protections were meant to stop attackers from stealing browser cookies, but StealC found a way to bypass them and steal old cookies to hijack Google accounts.
What's New in the 2025 Version
A fresh version of StealC was released to cybercriminals in March 2025. Since then, a few more updates have improved it even further. Experts who studied it found several key changes:
1. It can now install itself using different types of files, such as .exe programs, PowerShell commands, and software installers.
2. The new version uses strong encryption to hide its activity, making it harder for security tools to notice.
3. It now works better on modern computers and can delete itself after stealing data, leaving fewer traces behind.
4. Hackers can use built-in tools to adjust what kind of data StealC should look for.
5. It can even take screenshots of what’s on your screen, even if you use more than one monitor.
6. Alerts can be sent directly to hackers through the Telegram messaging app.
However, some older features were removed. For example, it no longer checks for virtual machines or downloads certain file types. Experts think this may be temporary and those features could return in later updates.
How It's Being Spread
StealC is now being spread using other malware. One example is Amadey, which helps deliver StealC to victims’ devices. Different attackers may use different methods depending on their goals.
How to Stay Protected
To avoid falling victim to malware like StealC:
• Avoid saving sensitive data like passwords in your browser.
• Turn on two-factor authentication for your accounts.
• Never download pirated software or apps from shady websites.
Cyberattacks are always evolving, so it’s important to stay informed and cautious while online.
The attack, referred to as ‘MrTonyScam,’ executes its attacks by sending messages to their targets compelling them to click on their RAR and ZIP archive attachments, and launching a dropper that downloads the subsequent stage from a GitHub or GitLab repository.
Oleg Zaytsev, Guardio Labs researcher states in an analysis published over the weekend, "Originating yet again from a Vietnamese-based group, this campaign uses a tiny compressed file attachment that packs a powerful Python-based stealer dropped in a multi-stage process full of simple yet effective obfuscation methods."
This payload is another archive file with a CMD file inside of it. The CMD file then contains an obfuscated Python-based stealer that exfiltrates all cookies and login information from various web browsers to a Telegram or Discord API endpoint that is under the control of an actor.
A significantly interesting tactic used by the threat actors is how they delete all cookies once they have stolen them in order to block their victims from their own accounts. They further hack the victim’s session with the help of the stolen cookies, changing passwords and thus acquiring complete control.
Also, there have been speculations that the threat actors are based in Vietnam, considering the presence of Vietnamese language references in the source code of the Python stealer. For instance, there has been the inclusion of ‘Cốc Cốc,’ which is a Chromium-based browser used popularly in Vietnam.
Guardio Labs discovered that the campaign has experienced a high success rate, with 1 out of 250 victims being estimated to have been infected over the last 30 days alone, despite the fact that the infection needs user input to download a file, unzip it, and execute the attachment.
Among other countries, the United States, Australia, Canada, France, Germany, Indonesia, Japan, Nepal, Spain, the Philippines, and Vietnam have reported the majority of the compromises.
"Facebook Accounts with reputation, seller rating, and high number of followers can be easily monetized on dark markets[…]Those are used to reach a broad audience to spread advertisements as well as more scams," Zaytsev noted.
The aforementioned reveal came in days after WithSecure and Zscaler ThreatLabz reported the newly launched Ducktail and Duckport campaigns that targeted Meta Business and Facebook accounts using ‘malverposting’ tactics.
"The Vietnamese-centric element of these threats and high degree of overlaps in terms of capabilities, infrastructure, and victimology suggests active working relationships between various threat actors, shared tooling and TTPs across these threat groups, or a fractured and service-oriented Vietnamese cybercriminal ecosystem (akin to ransomware-as-a-service model) centered around social media platforms such as Facebook," WithSecure noted.
Recently, a new Golang-based information stealer malware, named ‘Titan Stealer’ is being promoted by threat actors in their Telegram channel. Initial details regarding the malware were discovered by cybersecurity researcher Will Thomas in November 2022 by using the IoT search engine Shodan.
Titan is advertised as a malware builder that enables users to alter the malware binary's functionality and the type of data that will be extracted from a victim's system.
The malware, when launched, initiates a technique called ‘process hollowing’ in order to disseminate the malicious payloads into the memory of a legitimate process called AppLaunch.exe, Microsoft’s .NET ClickOnce Launch Utility.
According to a recent report by Uptycs security, researchers Karthickkumar Kathiresan and Shilpesh Trivedi say, “the stealer is capable of stealing a variety of information from infected Windows machines, including credential data from browsers and crypto wallets, FTP client details, screenshots, system information, and grabbed files.”
The Titan Stealer has been targeting web browsers, including Google Chrome, Mozilla Firefox, Microsoft Edge, Yandex, Opera, Brave, Vivaldi, 7 Star Browser, Iridium Browser, and others. The crypto wallets singled out are Armory, Atomic, Bytecoin, Coinomi, Edge Wallet, Ethereum, Exodus, Guarda, Jaxx Liberty, and Zcash.
Additionally, it has the ability to collect data from the Telegram desktop app and compile a list of the host's installed programs.
The gathered information is then transmitted as a Base64-encoded archive file to a remote server under the attacker's control. Additionally, the malware includes a web panel that enables threat actors to access the stolen data.
The exact approach used to distribute the malware is still unclear, but the threat actors have utilized numerous methods, such as phishing, malicious ads, and cracked software.
"One of the primary reasons [threat actors] may be using Golang for their information stealer malware is because it allows them to easily create cross-platform malware that can run on multiple operating systems, such as Windows, Linux, and macOS," says Cyble in its analysis of Titan Stealer. "Additionally, the Go compiled binary files are small in size, making them more difficult to detect by security software."
The findings come a little over two months after SEKOIA unveiled Aurora Stealer, another Go-based malware that is being used by a number of criminal actors in their campaigns.
The malware often spreads through websites that mimic a renowned software, with the same domains being continuously updated to host trojanized versions of different programs.
It is also found to be taking advantage of a tactic called padding in order to artificially inflate the size of the executables to as much as 260MB by adding random data, in order to evade detection by antivirus software.