Malware

What is malware?

Malware is the umbrella term for software designed to do things you don't want: steal your data, encrypt your files, spy on your activity, hijack your computing resources, or destroy your systems. It's one of the oldest categories of cybersecurity threats and remains one of the most prevalent.

The major types of malware include:

• Ransomware. Encrypts your files and demands payment for the decryption key. The most financially impactful malware category for businesses.
• Trojans. Disguised as legitimate software, trojans create backdoors that give attackers persistent remote access to compromised systems.
• Worms. Self-replicating malware that spreads across networks without user interaction, exploiting vulnerabilities to propagate automatically.
• Spyware. Silently monitors user activity, capturing keystrokes, screenshots, credentials, and other sensitive data.
• Infostealers. Specifically designed to extract stored credentials, browser cookies, cryptocurrency wallets, and authentication tokens.
• Cryptominers. Hijack computing resources to mine cryptocurrency, degrading system performance and increasing cloud costs.

How malware reaches your systems

Modern malware rarely arrives through a single channel. Common delivery methods include:

1. Phishing emails. Malicious attachments (Office documents with macros, PDF files, compressed archives) or links to drive-by download sites. Phishing remains the most common malware delivery vector.
2. Compromised software supply chain. Malware injected into legitimate software packages, open-source libraries, or vendor update mechanisms. The attacker compromises the supply chain, and legitimate users install the malware themselves.
3. Exploit kits. Automated toolkits hosted on compromised or malicious websites that probe visitors' browsers and plugins for vulnerabilities and deliver malware through discovered weaknesses.
4. Removable media and physical access. USB drives and other removable media that auto-execute malware when connected. Less common in cloud-native startups but still relevant.

Why malware matters for startups

1. Infostealers target developer credentials. Developer workstations are high-value targets because they contain credentials for code repositories, cloud consoles, CI/CD pipelines, and production infrastructure. A single infostealer infection on a developer's laptop can give attackers access to your entire stack.
2. Cloud costs spike from cryptominers. Cryptomining malware that compromises cloud compute instances can generate massive, unexpected cloud bills. Startups have reported five-figure bills from compromised AWS or GCP accounts running unauthorized mining operations.
3. Ransomware is existential for small businesses.
4. Compliance requires malware controls. SOC 2 and ISO 27001 both expect endpoint protection, malware detection, and incident response procedures for malware events. Auditors will ask what controls you have in place.

Startup-friendly malware defenses

• Endpoint detection and response (EDR). Tools like provide real-time malware detection and response on workstations and servers. Many offer startup pricing.
• Email security. Cloud email filtering catches most commodity malware before it reaches inboxes.
• Least-privilege access. If malware infects a developer's laptop, least-privilege IAM policies limit what the attacker can access with the compromised credentials.
• SCA for supply chain malware. Software Composition Analysis detects known malicious packages in your dependencies before they reach production.