What are remote access trojans (RATs)?

The National Cybersecurity Alliance defines RAT as “a type of malware that allows a hacker to control your device from anywhere in the world secretly.” Malware, or malicious software, are programs that infiltrates systems without the user’s knowledge or consent. Cybercriminals use this software to steal data, monitor activity, disrupt operations, or enable unauthorized access. This makes RATs particularly dangerous because they provide attackers with persistent, hidden control over infected devices.

Understanding remote access trojans

According to the study, The Ghost In The System: Technical Analysis of Remote Access Trojan, “the Remote Access Trojan (RAT), allows viewing and modifying user's files and functions in the system, monitoring and recording user activity, and using the victim's system to attack other systems. RATs can easily hide in the system with their advanced methods of infection and can be present as ghost entities in the system without getting caught by the security software.” According to the study, RATs are used by intelligence agencies and activist groups for blackmail and spying.

See also: FAQs: All things malware

How do RATS work?

The authors of the abovementioned study note that RATs typically infect a target system by tricking users into installing a modified or malicious file. These files are distributed via social media platforms such as Facebook and Instagram or via messaging services, either directly from the attacker’s server or via links shared by compromised accounts. In other cases, users may unknowingly download a program that contains the RAT embedded within it.

Another common infection method is the use of Java downloaders. When a victim visits a compromised or malicious website, hidden Java code is automatically downloaded and executed on the system without the user’s knowledge or consent. This allows the RAT to install silently in the background, making detection difficult.

Once installed, a RAT can activate the device’s webcam and microphone at any time. As long as the system is powered on and connected to the internet, attackers can view, record, or listen to conversations in the surrounding environment, even when the user is not actively using the device.

Common sources of RATs

According to the National Cybersecurity Alliance, RATs can infect a device using the following methods:

Phishing emails, texts, DMs, and calls

The targeted user may “receive an email, text, or social media direct message (DM) with an attachment or link that secretly installs the RAT when opened.”

Malicious downloads

Downloading a free app, cracked software, pirated media, or games could potentially include a hidden RAT.

Fake updates

Users may be tricked into downloading software updates that are malware. “Some websites are built to scare you into downloading these fake updates or antivirus software.”

Compromised websites

Visiting a malicious website can initiate an automatic download.

How to detect RATs

According to the National Cybersecurity Alliance, signs that your device might have a RAT include:

• Your device may slow down or freeze without explanation.
• Your internet connection may seem unusually busy, even when you’re not using it.
• You may find unknown apps or programs on your computer.
• Strange messages or pop-ups may start to show up.
• Your webcam light may flicker without you using it.

Defending against

According to the National Cybersecurity Alliance, the following can be implemented to prevent RAT installation:

• Users should not “open unexpected attachments or click links from unknown senders.”
• “Avoid shady sites, pirated software, or unverified apps.”
• Use antivirus software or a firewall.
• Frequently update software.

See also: HIPAA Compliant Email: The Definitive Guide (2026 Update)

FAQS

What can attackers do with a RAT?

Attackers can steal files, log keystrokes, capture passwords, activate webcams or microphones, take screenshots, and install additional malware.

How is a RAT different from other malware?

RATs give attackers ongoing, real-time access to a system, effectively allowing them to operate it remotely.

Can mobile devices be infected with RATs?

Yes. RATs exist for Android and other platforms, often disguised as legitimate apps or delivered through malicious downloads.

What should you do if you suspect a RAT infection?

Immediately disconnect the device from the network, notify your IT or security team, run a full malware scan, and consider a forensic investigation to assess potential data exposure.