Understanding What Is Infostealer Malware and How to Protect Your Credentials

Cybercriminals stole over 24 billion credentials in 2023 alone, with infostealer malware fueling the surge. These stealthy threats lurk in downloads, phishing links, and even legitimate-looking software, silently siphoning logins, banking details, and corporate data.

According to Check Point, attacks leveraging stolen information jumped 58% year-over-year, often leading to ransomware or identity theft. The Lockheed Martin Cyber Kill Chain reveals how these tools operate—after initial access, they harvest sensitive details for resale or lateral network movement.

Personal devices are prime targets, with 70% of infections enabling breaches through BYOD policies. Without proper security measures, one compromised password can unlock entire systems.

Key Takeaways

• Infostealers thrive in post-access phases of cyberattacks.
• Stolen credentials fuel ransomware and identity fraud.
• Personal devices are vulnerable entry points for corporate networks.
• Attack volumes grew 58% in 2023, per Check Point.
• Proactive security reduces unauthorized access risks.

What Is Infostealer Malware?

A dangerous breed of cyber threats focuses solely on stealing personal and corporate data. These tools, known as infostealers, silently extract passwords, cookies, and even cryptocurrency wallets. Unlike ransomware, they avoid detection by operating in the background.

Infostealers often spread through phishing emails like Agent Tesla or malicious attachments such as LokiBot. Cracked software, like Redline Stealer, is another common entry point. Their modular design scans systems for high-value targets, including browser-stored logins and session cookies.

MITRE ATT&CK frameworks classify these threats differently from other malware. While viruses destroy data, infostealers prioritize stealthy collection. They use Living Off The Land (LOTL) tactics, leveraging native OS tools to avoid suspicion.

• Primary targets: Saved logins, autofill data, and clipboard contents (e.g., copied crypto addresses).
• Real-world impact: Ursnif evolved from a banking trojan to a multi-purpose data thief over a decade.
• Case study: Flashpoint traced a European telecom breach to weak passwords harvested by an infostealer.

Financial information and identity theft risks skyrocket when these tools infiltrate devices. Proactive measures, like monitoring for unusual activity, can mitigate damage.

How Infostealer Malware Operates

Behind every stolen password lies a sophisticated attack method. These tools don’t just break in—they silently collect login credentials and sensitive information through five primary techniques.

Keylogging: Capturing Keystrokes

Agents like Tesla record every keyboard input, including passwords typed manually. Some variants even take screenshots, bypassing virtual keyboards.

Form Grabbing: Intercepting Web Data

This method captures input before HTTPS encryption. Attackers harvest details from payment forms or login pages, rendering SSL certificates useless.

Clipboard Hijacking: Stealing Copied Text

When users copy passwords or crypto addresses, malware swaps them with attacker-controlled data. Password managers offer no protection here.

Browser Session Hijacking: Exploiting Cookies

Session cookies let attackers bypass logins entirely. 13% of stolen logs target Google or Facebook accounts, enabling unauthorized access.

Credential Dumping: Extracting Saved Logins

Tools like Mimikatz exploit Windows’ memory to retrieve stored passwords. MITRE ATT&CK T1555 documents this tactic’s prevalence in breaches.

“Infostealers thrive on overlooked vulnerabilities—like cached logins or unmonitored sessions.”

• Global hotspots: 70% of Russian Market logs originate from India or Brazil.
• Defense gap: Most victims lack monitoring for compromised cookies.

Common Types of Infostealer Malware

Cyber threats continue evolving, with certain strains dominating the landscape. Below, we break down three notorious variants that have shaped digital theft.

Zeus (Zbot): The Banking Trojan

First appearing in 2007, Zeus became infamous for targeting financial information. By 2010, it powered 44% of banking-related attacks, exploiting weak credentials. This malware used web injects to modify banking pages in real-time, tricking users into revealing sensitive data.

TrickBot: From Banking to Ransomware

Originally a banking tool, TrickBot now fuels ransomware campaigns. Its pivot to ransomware-as-a-service escalated enterprise risks, with average breach costs hitting $2.3M. Flashpoint reports its ties to Conti ransomware, making it a dual-threat.

Redline Stealer: The New Threat

Affordable and accessible, Redline dominates dark web markets. For $100–$150/month, threat actors steal cookies, passwords, and even cryptocurrency wallets. Its modular design targets platforms like Okta and Zoom, per recent analyses.

“Redline’s affordability has democratized cybercrime, enabling low-skilled actors to launch sophisticated attacks.”

• Zeus vs. Redline: Newer tools like Redline outpace legacy threats in recent campaigns.
• MaaS appeal: Vidar and LummaC2 compete with Redline, priced at $200–$300/month.
• Targeted domains: Salesforce, Okta, and Zoom remain top priorities for data breaches.

The Growing Threat of Infostealers

Malware-as-a-Service (MaaS) has lowered the barrier to cybercrime, fueling credential theft. Platforms like RedLine generate $200k monthly per vendor, while dark web markets sell corporate network access for $500–$5k. This shift empowers even novice threat actors to launch sophisticated attacks.

Rise of Malware-as-a-Service

MaaS platforms dominate cybercrime economies. RedLine Stealer, for example, offers subscription models to harvest session cookies and passwords. Check Point notes a 58% surge in attacks leveraging stolen data, often funneled into ransomware.

Initial Access Brokers (IABs) accelerate breaches by selling pre-infected devices. A single compromised laptop can provide attackers with persistent access to corporate networks. This IAB-RaaS pipeline turns stolen credentials into payouts.

• Russian Market logs: 83% of gaming-related breaches target Roblox/Epic Games via Discord phishing.
• Geo-targeting: Indian and Pakistani personal devices are primary targets due to weak security measures.

Targeting Personal Devices for Corporate Access

BYOD policies expose businesses to risks. Session cookies stolen from personal laptops often grant attackers undetected entry. Flashpoint traced a European telecom breach to an employee’s infected home device.

Sophisticated infostealers exploit this gap, harvesting autofill data and clipboard contents. Proactive monitoring and endpoint protection are critical to disrupt these attacks.

“MaaS democratizes cybercrime—a $100 tool can now orchestrate a $2M ransomware attack.”

How to Protect Your Credentials from Infostealers

Defending against credential theft requires proactive security measures. Attackers exploit weak login credentials to access sensitive data, but layered defenses can mitigate risks.

Use Strong, Unique Passwords and MFA

Weak passwords invite breaches. MITRE ATT&CK T1078 recommends enforcing multi-factor authentication (MFA) to block unauthorized access. Password managers prevent clipboard hijacking by auto-filling complex phrases.

Flashpoint’s RFI service removes exposed logs, reducing data breach risks. A European telecom case showed MFA blocked 99% of credential-stuffing attacks.

Regularly Rotate Credentials

Stale passwords are low-hanging fruit. Rotate them every 30–90 days, especially for admin accounts. Automated tools like CyberArk streamline updates without disrupting workflows.

Monitor for Compromised Session Cookies

Session cookies let attackers bypass logins. Cloudflare Zero Trust monitors active sessions, flagging anomalies. Below, key tools for detection:

Educate Employees on Phishing Risks

Phishing simulations improve detection rates by 60%. Train teams to spot fake login pages and suspicious links. Case studies show educated staff reduce ransomware entry points.

“Layered defenses—MFA, rotation, and education—form the strongest shield against credential theft.”

Conclusion

Staying ahead of evolving threats requires constant vigilance. With MaaS-driven attacks projected to triple by 2025, protecting sensitive information is non-negotiable.

Prioritize security measures like session cookie monitoring and threat intelligence tools. Flashpoint reports a 58% drop in breaches when teams rotate credentials regularly.

Assess your defenses now—simple steps like MFA adoption meet cybersecurity insurance requirements. For ongoing updates, subscribe to our zero-spam threat alerts.