As cyber threats evolve, infostealers—data-harvesting malware—are gaining traction in the criminal underground. These tools are used to siphon sensitive information like banking credentials and email passwords, which are then sold on the dark web, driving identity theft and financial fraud.

Infostealers are increasingly central to ransomware campaigns, acting as reconnaissance tools to gather login credentials, enabling attackers to move laterally across networks and escalate privileges before deploying ransomware. The rise of malware-as-a-service (MaaS) has made these tools widely accessible, even to those with little technical expertise, putting organizations of all sizes at risk.

In this interview, Erik Eisen, CEO of CTI, joins CloudTweaks to discuss the growing infostealer threat and what businesses can do to protect themselves.

Erik, infostealers have become a prominent tool in the cybercriminal arsenal. Can you explain how they operate and why they’ve gained such popularity in recent years?

Infostealers are a type of malware designed to harvest sensitive information, such as login credentials, browser-stored passwords, and financial data, from compromised devices. Their popularity stems from their efficiency and low operational cost for attackers. Unlike ransomware, which demands a visible payment, infostealers quietly exfiltrate data, allowing cybercriminals to monetize stolen credentials through resale or secondary attacks. This stealth and scalability make them an attractive option in the modern cybercrime landscape.

How do infostealers differ from other types of malware, like ransomware or Trojans, in terms of functionality and objectives?

While ransomware focuses on encrypting data to demand a ransom and Trojans often act as gateways to deploy additional malicious payloads, infostealers are specialized for data exfiltration. Their primary objective is to gather information quickly and quietly, often before the victim realizes they’ve been compromised. This makes them ideal for attackers who prioritize long-term access to systems or who want to sell data on dark web marketplaces.

It’s noted that infostealers often act as reconnaissance tools in ransomware campaigns. Could you elaborate on how attackers use stolen credentials to plan and execute more damaging attacks?

Infostealers often serve as the first phase of a broader attack. By stealing credentials, attackers gain access to networks, accounts, and sensitive systems. These credentials enable reconnaissance, allowing threat actors to identify high-value targets, map out the network, and escalate privileges. Once they’ve gathered enough intelligence, they can deploy ransomware in a way that maximizes impact, such as targeting backup systems or critical infrastructure, increasing the likelihood of a ransom payment. 

What are the most common infection vectors for infostealers, such as malvertising or phishing emails, and what makes these methods so effective?

Phishing emails and malvertising are particularly effective because they exploit human behavior and trust. Phishing emails often mimic legitimate communications, prompting users to click on malicious links or download infected attachments. Similarly, malvertising leverages compromised or deceptive ads to direct users to malicious sites. Both methods are low-cost, high-return strategies for attackers, and they capitalize on the wide reach of email platforms and online advertising networks.

The MaaS model has made deploying malware, including infostealers, accessible to those with little technical expertise. How does this impact the overall threat landscape, particularly for smaller businesses?

Malware-as-a-Service (MaaS) significantly lowers the barrier to entry for cybercrime. With ready-made malware kits available for purchase, even individuals without technical skills can launch attacks. For smaller businesses, this democratization of cybercrime is particularly concerning because they often lack the resources for advanced cybersecurity measures, making them attractive targets. This shift has led to a surge in the volume and sophistication of attacks.

As cybercriminals continue to innovate, what are some of the newer tactics they’re using to deploy infostealers and evade detection?

Attackers are increasingly employing advanced obfuscation techniques, such as polymorphic code that changes signatures to evade antivirus detection. They also use encrypted communication channels and exploit zero-day vulnerabilities to deploy infostealers. Additionally, cybercriminals are leveraging social engineering on platforms like social media to trick users into downloading malicious software, demonstrating their ability to adapt to evolving digital landscapes. 

For organizations looking to protect themselves, what are the most effective strategies or best practices for mitigating the risk of infostealer infections?

Organizations should prioritize a multi-layered defense strategy. This includes deploying robust endpoint protection, keeping software and systems up-to-date, and conducting regular security audits. Network segmentation and implementing a least-privilege access model can limit the damage in case of a breach. Additionally, continuous monitoring for anomalous activity can help detect and respond to threats in real-time.

You’ve emphasized the importance of browser security and multi-factor authentication. How do these specific measures help in reducing the effectiveness of infostealers?

Infostealers often target browser-stored credentials, so using browser security features, like disabling password storage, can mitigate risks. Multi-factor authentication (MFA) adds an extra layer of defense, making it harder for attackers to gain access even if they’ve stolen login credentials. Together, these measures significantly increase the effort required for a successful attack, deterring many threat actors.

Cybersecurity often involves human behavior. How can businesses address the human element, such as employee training, to prevent the accidental introduction of infostealers into their networks?

Employee training is critical for building a culture of cybersecurity awareness. Regular training sessions on recognizing phishing attempts, avoiding suspicious downloads, and following secure browsing practices can empower employees to act as the first line of defense. Simulated phishing exercises and clear reporting channels for suspected threats can further enhance an organization’s resilience. 

Can you tell us more about CTI, your mission, and the specific ways your company helps organizations stay ahead of threats like infostealers?

At CTI Technical Services, our mission is to empower organizations with cutting-edge cybersecurity solutions that protect their critical assets. We specialize in proactive threat management, including advanced endpoint protection, security audits, and employee training programs. Our expertise in AI and cybersecurity allows us to detect and respond to threats like infostealers in real-time, helping businesses stay ahead in an ever-evolving threat landscape.

By Randy Ferguson