In recent years, I’ve become particularly alert to one type of malware: infostealers. Typically distributed in a malware-as-a-service model, infostealer malware is typically used to steal data, remaining silent for as long as possible—and that’s just one of the issues.
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Infostealer Malware Targets Your Private Data
The first reason I worry about infostealing malware is that in 2024, it was responsible for the leak of 3.9 billion passwords in a single year! Security research firm KELA revealed the startling figure in its 2024 State of Cybercrime report, along with the information that more than 4.3 million devices were infected with infostealer malware.
Following that, another security research firm, Huntress, released its 2025 Cyber Threat Report—and revealed that in 2024, infostealers accounted for a staggering 25 percent of all cyber attacks.
So, while attackers have used infostealer malware for a long time, in the past few years, it’s really ramped up.
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It Can Quietly Pilfer Different Types of Sensitive Data in Bulk
Another worry is that infostealers steal data lifted from multiple accounts of a single person. It can siphon your sensitive data, including:
- Personal data (addresses, phone numbers, social security numbers)
- Emails and chat logs
- Browser data (history, cookies, bookmarks)
- Financial information (banking details, credit card numbers)
- Login credentials (usernames and passwords)
- Cryptocurrency accounts
Some infostealing malware types capture your keystrokes, like the snake keylogger, while others have clipboard-hijacking features that steal information you copy into your device’s clipboard. Others have file-harvesting components that go through your files and emails, and most have screen-capture features that take screenshots while you are entering your credentials or have sensitive personal information on your screen.
What’s worse is that these infostealers can quietly infect your system and do all this covertly without you noticing anything suspicious is happening. Attackers also use advanced obfuscation techniques to evade security detection.
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The Infostealer Threat Is Everywhere
Infostealers are spread using phishing and non-phishing methods and executed on almost all popular platforms. You’ll find hackers trying to lure you into downloading infostealing malware on video-sharing sites like YouTube, social media apps like Facebook and LinkedIn, and fake attachments sent to your email or fake human verification pages.
Pirated software is a primary source for infostealer malware, as you might expect. However, there have also been examples of infostealing malware embedded into stolen software uploaded to legitimate sites. In February 2025, a game uploaded to Steam, PirateFi, was found to contain infostealer malware. Although Steam-owner Valve quickly removed the free-to-play game from its platform, it managed to infect hundreds of machines.
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Infostealer Malware Is Often Used As a Gateway for Bigger Attacks
Now, here’s one that really worries me. Many sinister cybercrime attacks can be traced back to an initial infostealer infection. The malware serves as reconnaissance for hackers to launch bigger attacks, using the data collected and initial access exploited by the infostealers.
For example, after hackers infect your work device with an infostealer, they may steal corporate login credentials and infiltrate your organization’s network. Then, they will scan the system for other valuable data or install backdoors and remote access tools. Finally, they will either steal corporate data in bulk or encrypt the data to cripple operations and demand a ransom.
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The Infostealer Threat Is Expected to Grow
The widespread Infostealer infections are creating a global malware pandemic. According to Check Point’s 2025 Cybersecurity Report, infostealer malware surged by 58%, and organizations in Europe, the Middle East, and Africa saw a big increase in attacks. Other continents are also facing the infostealer problem. For instance, a campaign to distribute the SYS01 InfoStealer malware impacted millions globally, spanning regions including Australia, Asia, North America, and Europe.
With advanced obfuscation techniques and the use of AI to supercharge phishing campaigns, the infolstealer threat is expected to continue to grow in scale and sophistication. Infostealers like the notorious Lumma strain are expected to continue to plague individuals and businesses, so it is important to stay vigilant.
Infostealer malware is far from the only threat facing us online. But it’s definitely the one I’m most worried about at the current time!
