Stealer Malware Exposed: The Key Suspect in Identity Credential Theft

You wake up to an unusual notification—a new device logged into your work email account overnight. But it’s not yours.

In fact, the device location is in a different country. You scramble to reset the password, but it no longer works. After too many failed attempts, you’re locked out. It’s too late. The hackers got in and shut you out. Sounds like an exaggeration? Unfortunately, it’s not. This is the sad reality of identity credential theft. With every passing year we add more devices, apps, and cloud storage spaces, and with this growth, the threat of identity credential theft grows. Browsers, streaming services, and online retailers store our purchasing habits, preferences, and even payment methods—information that, in the wrong hands, can be dangerous.

The majority of people trust their device and storage providers to safeguard their data. They’re aware of phishing attacks and know they should use strong passwords, update them regularly, never use them twice, and use multifactor authentication when available. Yet, the Verizon Data Breach Report shows that 49% of all breaches were due to poor password management.

It’s no surprise then, that 46% of US internet users had their passwords stolen last year, according to a recent study commissioned by Forbes Advisor. The 2024 Snowflake data breach underscored the consequences of weak security practices and saw sensitive customer data from over 100 companies exposed. While the full extent of the damage remains unclear to this day, stolen information from millions of Snowflake customers was posted for sale on Breach Forums, putting countless individuals at risk.

The rise of infostealer malware

Unfortunately, even keeping perfect password hygiene might not safeguard data. Cybercriminals have increasingly turned to stealer malware (infostealer)—malicious software designed to quietly extract login credentials and other sensitive information. Having been around for nearly two decades, stealer malware has evolved into a more sophisticated and widespread threat, now easily accessible through Malware-as-a-Service (MaaS) models, making it a growing weapon of choice in the cybercrime ecosystem.

Popular stealer malware families include:

• RedLine Stealer: One of the most widely used infostealers, RedLine extracts credentials, browser-stored data, cryptocurrency wallets, and system information. It’s sold as Malware-as-a-Service (MaaS) and frequently updated to evade detection.
• Vidar Stealer: A powerful infostealer capable of stealing passwords, browser data, cryptocurrency wallets, and application credentials. Vidar is often distributed via malicious ads, fake software downloads, and phishing campaigns.
• Raccoon Stealer: A well-known credential-stealing malware that collects passwords, cookies, autofill data, and crypto wallets. Though its operations temporarily paused in 2022, it has since resurfaced with updated capabilities.
• Lumma Stealer: A newer but fast-growing malware that steals credentials, cryptocurrency wallets, and system data, often sold on underground forums as a subscription-based service.

What is stealer malware?

Stealer malware (or infostealer) is designed to steal any critical information stored on a device or network. It looks for passwords, of course, but the data it is after is far more varied. It includes:

• Credit card details
• Cryptocurrency wallet information
• Autofill data
• Account credentials, not only passwords and session cookies and even multifactor authentication (MFA) data
• Browser data, like cookies and extensions
• Operating system data and browser configurations
• IP addresses and user location
• Hardware specs, language, hostname, and installed software
• Communication data
• Files and documents
• Logs

Some variants even drop keystroke loggers to capture everything you type—including passwords that aren’t saved anywhere.

How does infostealer malware work?

Initial Infection

Stealer malware gets in through the usual suspects: phishing, fake software downloads, or second-stage payload drops from other malware. It can even be as simple as a drive-by download from an infected website.

Data Collection

Once inside, the malware hunts for precious data. A favorite collection tool is clipboard hijacking. It steals or replaces crucial information, like account numbers and passwords, saved within the user's clipboard. Other methods include screen capture, form grabbing, and seizing cookies. It can even decide to dig deeper if it finds crypto wallets or banking apps.

Data Exfiltration

The stolen data needs to be sent back to the attacker. Stealer malware creates a covert communication channel by merging with a regular traffic stream and transmitting obfuscated data. During this process, it may also deploy additional malware, allowing remote control and further system compromise.

Monetization & Exploitation

Stolen data doesn’t sit around and twiddle its thumbs. Stolen data is quickly sold to Initial Access Brokers (IABs), who then sell them through various channels used by cyber-criminals.

How to safeguard your data

InfoStealer malware stealthiness and sophistication make detection and prevention difficult. However, early detection of leaked credentials can help level the playing field.

If users whose credentials have been compromised are alerted early enough, they can change their passwords before cyber criminals exploit them. For organizations and businesses, early warning is a crucial head start, enabling SOC teams to investigate further infections before they escalate.

Real-time cyber intelligence: your best defense

To stay ahead of these evolving threats, you need real-time cyber threat intelligence that scours the clear, deep, and dark web to detect and prevent attacks. Bitsight delivers:

• 7 million intelligence items collected daily from over 1,000 underground forums and marketplaces.
• Tracking of over 700 APT groups, 4,000 types of malware, and 95 million threat actors.
• AI-driven enriched insights that provide security teams with insights into the source of threats in less than a minute.
• Always-on AI assistant to answer queries and make threat intelligence accessible to all.
• Customizable alerts for compromised credentials and leaked data.
• Seamless integration via SaaS Portal, API, or third-party integration tools.

With stealer malware lurking in the shadows, quick detection and response is your best defense.

Don’t wait for cyber criminals to steal your credentials. Get ahead of real-time threats now. Book a demo here to learn how.