Spyware is a type of malware designed to gather data on users, devices, and networks. It then sends this data to a third party without the victim’s knowledge or consent. 

There are many different types of spyware. Some collect relatively low-value data to send to advertisers and data brokers. Others focus on highly sensitive information like user login credentials and financial details. 

Sophisticated threat actors may use spyware to perform reconnaissance on their targets. The initial spyware infection provides context and data attackers can use to launch more elaborate and disruptive attacks later on. As a result, even relatively harmless spyware infections can lead to highly disruptive cyberattacks. 

How does spyware work? 

As one of the most common malware threats, a huge number of spyware variants exist, and each one operates differently. The ability to steal data is the single characteristic all spyware shares. 

Some spyware variants monitor user activity, taking screenshots and capturing keyboard inputs. Others track web browser usage, or search for specific types of sensitive files. 

Although these attack scenarios are all very different, they generally follow a standard series of steps: 

1. Infiltration. First, spyware must be installed on the victim’s device. This may happen through a malicious application package, a spoofed website, or a compromised email attachment. 

1. Monitoring and capture. Once installed, spyware begins stealing information about the device and its users. It may look for specific files to steal, monitor the device’s usage, or capture data in real-time. 

1. Transmission. Once the data has been captured, it must be communicated to the threat actor responsible. This can happen in a variety of ways, but it generally requires establishing an outbound connection to an attacker-controlled server or device. 

10 Types of Spyware 

Many different types of spyware exist, but most fall into one of the following categories:

• Adware primarily tracks users’ web history and browser activity to support third-party advertisers. While not as damaging as ransomware or other disruptive threats, adware still erodes user privacy and expands the enterprise attack surface. 
• Infostealers scan devices looking for specific types of information and then exfiltrate the data. Infostealers can conduct network reconnaissance, collect login credentials, and infiltrate sensitive databases. 
• Keyloggers are a type of infostealer that records input commands sent to the infected device. That can include usernames, passwords, chat messages, website URLs, and more. 
• Rootkits enable threat actors to infiltrate devices and interact with them as administrators. This gives them the ability to bypass many security controls and cover their tracks well. 
• Red Shell spyware is specific to certain PC games. Manufacturers use this type of data to track user interactions with games, usually to improve the gaming experience and obtain valuable marketing data. 
• System monitors track user activity on their device. They may capture information about messages sent, websites visited, or capture screenshots of user activity. 
• Tracking cookies are a legal, regulated form of spyware. Hackers may use techniques like cookie poisoning or hijacking to gain access to victims’ devices by exploiting vulnerabilities in the way web browsers use cookies. 
• Trojan horses enter the system through Trojan malware, which is a type of malware that pretends to be legitimate software. Once installed, it delivers a malicious payload, which can include spyware. 
• Apple device spyware targets Apple Mac computers, usually with the same objectives as spyware that targets Windows operating systems. Common macOS spyware variants steal login credentials, install backdoors for remote code execution, and capture screenshots. 
• Mobile device spyware focuses on data unique to mobile devices, like call logs, contact lists, GPS location data, and SMS messages. Some mobile spyware variants can compromise microphone and camera hardware on Android and iOS devices. 

How spyware impacts your security posture 

Since there are many different kinds of spyware, each variant can have a unique effect on your overall security posture. At the top end of the threat spectrum, keyloggers and credential infostealers can lead to catastrophic insider attacks that disrupt business operations and cause significant losses. 

But not all spyware has an immediate disruptive impact on enterprise IT operations. Relatively harmless forms of adware may simply annoy users with a higher volume of pop-up ads. However, even these types of spyware can have a profound impact on your organization’s security risk profile. 

Your security team needs to authorize and validate every software application that runs on the enterprise network. When a threat actor successfully installs spyware on a network asset, it means that a vulnerability has been exploited. Nothing stops another threat actor from leveraging the same vulnerability in a far more disruptive attack. 

Similarly, the spyware itself adds significant unknowns to your organization’s risk profile. Without comprehensive detection, investigation, and response, there is no way to know the difference between an annoying adware infection and a potentially disastrous credential-based attack. 

How to prevent spyware 

Cybersecurity leaders primarily prevent spyware using technologies and policies that address the infiltration stage of spyware infection. For example, security tools that prevent users from downloading attachments from untrusted sources may block spyware installations from taking place. 

The transmission phase is also susceptible to certain prevention-based technologies. Data loss prevention and anti-data exfiltration tools may prompt users to authenticate before they allow sensitive data to leave the network. If spyware attempts to send sensitive login credentials to an external destination, this kind of tool may block it. 

Some advanced next-generation firewalls are capable of preventing spyware from establishing external connections and exfiltrating data. However, achieving this level of performance from a firewall requires in-depth customization and configuration. 

How to detect and remove spyware 

Detection-based workflows provide security teams with powerful tools for mitigating spyware threats. The infiltration phase is susceptible to Endpoint Detection and Response (EDR) technologies that may activate when untrusted applications install themselves on covered devices. XDR technology can expand that coverage to include servers, web applications, and cloud environments as well.  

At the monitoring and capture phase, both Network Detection and Response (NDR) and Security Information and Event Management (SIEM) platforms may register unusual behavior related to spyware infection. NDR may uncover abnormal connection patterns between devices on the network, while SIEM may trigger alerts due to unusual log data coming from network assets.

Both NDR and SIEM technologies also provide invaluable visibility into the spyware transmission phase. If a network asset establishes an unexpected connection to an external server and starts sending data, analysts will need to investigate that behavior to find out if it is malicious in nature. 

Lastly, if your security team fails to mitigate the spyware threat entirely, it can still detect malicious insiders and credential-based attacks with User Entity and Behavioral Analytics (UEBA). This technology triggers alerts when authorized users deviate from their routine behavior, potentially indicating that an attacker has gained control over a network asset. 

Protect your organization against spyware threats 

Securing your organization against spyware is vital for maintaining data privacy and securing sensitive assets. Reputable managed detection and response vendors like Lumifi can help you implement and configure the technologies you need to consistently neutralize spyware threats. 

Find out how our managed detection and response package can help you safeguard sensitive data from spyware threats. Gain 24/7 monitoring and response with world-class product expertise delivered from our SOC Type II-compliant Security Operations Center (SOC).