What Are Infostealers and Why SMBs Are Prime Targets
Infostealer malware is one of the fastest-growing threats to small businesses. Learn how these attacks work and why your company may already be compromised.
The Silent Threat Lurking in Your Business
Infostealer malware represents one of the most insidious threats facing small and medium-sized businesses today. Unlike ransomware that announces itself with dramatic encryption and ransom demands, infostealers work silently—harvesting credentials, session cookies, and sensitive data without any visible indication of compromise. According to IBM's 2025 Cost of a Data Breach Report, the average time to detect a breach is 241 days, giving attackers months of undetected access to your systems.
The Rising Threat to Small Businesses
The statistics paint a stark picture. In 2025, 46% of small businesses experienced a cyberattack in the past year, with 88% of SMB breaches involving ransomware or malware.
Credential theft now accounts for 16% of all data breaches, making it one of the most common attack vectors. When a breach does occur, the financial impact is devastating—IBM's 2025 report shows the global average breach cost at $4.44 million, with U.S. companies facing an all-time high of $10.22 million.
How Infostealers Work
Infostealers are a category of malware designed specifically to extract valuable information from infected devices. Once installed—often through phishing emails, malicious downloads, or compromised websites—they systematically collect sensitive data.
What They Steal
- Saved passwords from browsers and password managers
- Session cookies that can be used to bypass authentication
- Cryptocurrency wallet data and financial information
- Email credentials and contact lists
- VPN and remote access credentials
- Business documents and sensitive files
The Malware-as-a-Service Economy
What makes infostealers particularly dangerous is the ecosystem surrounding them. Criminal groups operate these tools as services, with variants like RedLine, Raccoon, and Vidar available for purchase or rent on dark web marketplaces.
The stolen data—called "logs"—is then sold to other criminals who specialize in exploiting specific types of access. This industrialized approach to cybercrime means even unsophisticated attackers can deploy highly effective infostealer campaigns.
Why Small Businesses Are Prime Targets
You might assume that attackers focus on large enterprises with valuable data. The reality is quite different—small businesses are attractive targets for several reasons.
Weaker Security Posture
Most SMBs lack dedicated security teams, enterprise-grade tools, and formal security policies. This makes initial compromise significantly easier.
Limited budgets mean many small businesses rely on basic antivirus software that struggles to detect modern infostealers. Without proper endpoint protection, these threats slip through undetected.
Gateway to Larger Targets
Small businesses often serve as vendors, suppliers, or partners to larger organizations. Compromising an SMB can provide a pathway into more valuable enterprise networks through supply chain attacks.
Attackers exploit these trusted relationships to move laterally. Your compromised credentials could be the key to breaching a Fortune 500 company.
Valuable Data Without Enterprise Protection
SMBs hold customer data, financial records, and business secrets that are valuable to criminals. Banking credentials, client information, and proprietary business data all have significant black market value.
Yet they rarely have the same protections as larger companies. This combination of valuable assets and weak defenses creates an ideal target.
Lower Risk for Attackers
Attacks on small businesses rarely make headlines or trigger major law enforcement investigations. This makes them lower-risk targets for cybercriminals who can operate with relative impunity.
The lack of media attention also means many SMBs don't realize how common these attacks are. They assume they're too small to be targeted, right up until they're compromised.
Signs Your Business May Be Compromised
Infostealer infections often go undetected for months or even years. The 241-day average detection time means attackers have ample opportunity to exploit stolen credentials.
Common Warning Signs
Unusual login attempts from unfamiliar locations or countries may indicate stolen credentials in use. Pay attention to failed login attempts, especially during off-hours.
Employees receiving password reset emails they didn't request is a red flag. Attackers often trigger these when testing stolen credentials.
Unexpected changes to financial accounts or vendor payment details could signal account compromise. Business email compromise often follows infostealer infections.
Browser extensions you don't recognize may be malicious. Some infostealers install extensions to maintain persistence and steal additional data.
Customers reporting phishing emails that appear to come from your company suggests email account compromise. Attackers use stolen email access to launch targeted phishing campaigns.
Protecting Your Business
Prevention is far more cost-effective than recovery. With average breach costs exceeding $4.44 million globally, investing in security measures delivers significant ROI.
Implement Multi-Factor Authentication
MFA is your strongest defense against credential theft. Even if passwords are stolen, attackers can't access accounts without the second factor.
Deploy MFA across all business systems, especially email, financial accounts, and remote access tools. Hardware security keys provide the strongest protection against sophisticated attacks.
Use a Business Password Manager
Enterprise password managers prevent employees from saving credentials in browsers, a primary target for infostealers. They also enable strong, unique passwords for every account.
Centralized management lets you quickly rotate credentials if compromise is suspected. This rapid response capability can significantly limit damage from a breach.
Deploy Endpoint Detection and Response
Modern EDR solutions can detect and block infostealer activity, even from previously unknown variants. Behavioral analysis identifies suspicious processes attempting to access stored credentials.
EDR provides visibility into what's happening on every device in your organization. This visibility is crucial for detecting the subtle signs of infostealer infection.
Regular Security Awareness Training
Employees need to recognize phishing attempts and suspicious downloads that deliver infostealer malware. Given that 88% of SMB breaches involve malware, human vigilance is critical.
Training should be ongoing, not a one-time event. Regular phishing simulations help reinforce secure behaviors and identify employees who need additional support.
Monitor the Dark Web
Services that monitor for your company's credentials appearing in data breaches can provide early warning of compromise. The sooner you know about stolen credentials, the faster you can respond.
Dark web monitoring helps you discover breaches during that critical 241-day detection window. Early detection dramatically reduces the potential damage from compromised credentials.
Key Takeaways
Infostealers represent a persistent, evolving threat that specifically targets the credentials and data small businesses depend on. The silent nature of these attacks means that by the time you notice a problem, significant damage may have already occurred.
With 46% of small businesses experiencing cyberattacks annually and credential theft accounting for 16% of breaches, the question isn't if you'll be targeted—it's when. The 241-day average detection time gives attackers months to exploit stolen credentials and pivot to more damaging attacks.
Proactive security measures—particularly MFA, endpoint protection, and employee training—are essential defenses. The cost of prevention is minimal compared to the $4.44 million average breach cost.
If you suspect your business may be compromised, immediate action is critical to limit the damage. Every day of delay gives attackers more time to monetize your stolen data and expand their access.
Need to assess your exposure to infostealer threats? Get a comprehensive security assessment from SimplCyber that identifies your risks and provides actionable recommendations.