How Does Ransomware Infect a Computer?
Updated on September 24, 2026, by Xcitium
How Does Ransomware Spread?
Ransomware spreads through phishing emails, malicious attachments and links, compromised credentials, vulnerable internet-facing systems, malicious downloads, and compromised third parties. After attackers gain initial access, they may steal credentials and move laterally through connected systems, remote services, and network shares before deploying ransomware across multiple devices.
As malware variants continue to evolve, ransomware is fast becoming the most dangerous threat of all times. Financial gain is the primary motivation behind ransomware attacks.
Unlike many other malware programs that allow cybercriminals to steal valuable data from victims, ransomware directly targets the victims, holding their computer files hostage (using encryption) for a ransom. In recent years, there is not only an increase in the number of ransomware attacks, but the level of sophistication in those ransomware attacks has also increased.
Even though ransomware is considered one of the most advanced malware programs, they have an inherent vulnerability — ransomware must establish a communication channel with its creator to initiate the process of encrypting the victim’s computer. In the process of communicating with the hacker, most ransomware variants generate a signature on the network which can be detected.
Today, ransomware programs are more advanced and stealthy, with some recent variants operating quietly in the background without making a single call to the hacker. Some ransomware variants even remove the data recovery options by encrypting the mapped network drives, deleting files and system restoration points.
10 Common Ways Ransomware Spreads
Ransomware attacks can begin and expand through several routes:
- Phishing emails
- Malicious attachments
- Malicious links and downloads
- Stolen or compromised credentials
- Exposed remote-access services
- Unpatched software vulnerabilities
- Pre-existing malware infections
- Network and lateral movement
- Compromised third parties
- Removable media and other connected systems
Modern ransomware operations do not always spread automatically like a computer worm. Attackers may manually move through a compromised network before deploying ransomware broadly.
How Ransomware Spreads at a Glance
| Spread Method | How It Works | Key Defense |
|---|---|---|
| Phishing | Tricks users into opening malicious content | Email security and training |
| Malicious attachments | Executes malware or a downloader | Attachment filtering |
| Malicious links | Directs users to malicious content | Web/DNS protection |
| Stolen credentials | Gives attackers legitimate account access | MFA and identity security |
| RDP/remote access | Provides remote entry or movement | MFA and restricted access |
| Vulnerability exploitation | Exploits unpatched systems | Patch management |
| Precursor malware | Establishes access before ransomware | Endpoint protection/EDR |
| Network movement | Attackers move between connected systems | Segmentation and monitoring |
| Third-party compromise | Trusted access is abused | Third-party access controls |
| Removable media | Malware moves through connected storage | Device and application controls |
Initial Infection vs. Ransomware Spread
These are related but different stages.
| Initial Infection | Ransomware Spread |
|---|---|
| Gets attackers into an environment | Expands access after compromise |
| May begin with phishing | May use stolen credentials |
| May exploit a vulnerable service | May use remote services |
| Usually affects an initial account/device | Can reach many endpoints |
| Establishes a foothold | Enables broader ransomware deployment |
Understanding this difference is important because stopping the initial malicious file is only one part of ransomware defense.
Can Ransomware Spread Through Network Drives?
Yes. Ransomware or attackers operating inside a compromised network may affect accessible network shares, mapped drives, servers, and other connected resources.
The extent of the damage depends on factors such as:
- Account permissions
- Network architecture
- Segmentation
- File-share access
- Security controls
- Ransomware behavior
Users should not have unnecessary write access to sensitive network locations.
Can Ransomware Spread From One Computer to Another?
Yes. Ransomware incidents can expand from one compromised computer to other systems when attackers obtain credentials, access connected resources, exploit vulnerabilities, or use network-management mechanisms.
Some malware can also include self-propagating capabilities.
This is why quickly isolating a suspected infected endpoint can be critical.
Can Ransomware Spread Through Wi-Fi?
Ransomware does not normally spread simply because two devices use the same Wi-Fi network.
However, devices on the same network may be exposed if attackers or malware can:
- Reach vulnerable services
- Access shared resources
- Use compromised credentials
- Exploit poor network segmentation
Secure network configuration and endpoint protection remain important.
How Fast Can Ransomware Spread?
The speed varies significantly.
A ransomware payload may encrypt accessible files rapidly once executed, but a broader ransomware intrusion can involve attackers remaining in an environment while they:
- Steal credentials
- Explore systems
- Escalate privileges
- Access servers
- Disable security controls
- Target backups
- Steal information
Encryption may occur only after these earlier stages are complete.
Organizations should therefore investigate suspicious activity before encryption occurs rather than waiting for a ransom note.
How Ransomware Spreads?
Ransomware infects a computer when a user downloads or runs ransomware-infected files. Attackers hide such files in a seemingly begin software, so it is advisable to practice safe computing habits.
#Malicious Emails
Email is the most common way by which ransomware spreads. The Ransomware is usually disguised as an email attachment and sent to unwary users. If the user opens such email attachments, it can lead directly to an infection. Another way used by cybercriminals is hiding the ransomware links in a button or the body of the email.
When clicked, it then redirects the user to a malicious website that leads to an infection. Hence, it is advisable that you verify the authenticity of any file or email attachments from unknown sources, before opening it.
#Free Software
Hackers lure unwary users into downloading ransomware by hiding malicious ransomware codes within cracked versions of different software such as games, adult content, online game cheats, and many more.
How to Stop Ransomware From Spreading
Use multiple security controls:
- Patch operating systems and applications.
- Enable MFA.
- Protect email from phishing.
- Restrict unnecessary remote access.
- Apply least privilege.
- Deploy endpoint protection and EDR.
- Segment networks.
- Monitor suspicious authentication activity.
- Use application controls.
- Protect and isolate backups.
- Scan for vulnerabilities.
- Train employees to recognize attacks.
Layered defenses are important because ransomware attacks can use multiple entry and propagation methods.
Ransomware Prevention Tips
- Make sure to download files and other software only from reputable websites.
- Install a good firewall program like Xcitium Firewall.
- Do not open links, suspicious emails or attachments from unknown senders.
- Most important of all, make sure to download and install a good antivirus program like Xcitium Antivirus.
The best way to prevent ransomware is by using Xcitium Antivirus. In case of organizations, Xcitium Advanced Endpoint Protection (AEP) is the ideal solution.
With an in-built containment engine that automatically contains all untrusted processes and applications in a secure virtual environment, Xcitium AEP provides complete protection against any malicious software including ransomware.
For unknown files, Xcitium’s local, and cloud-based Specialized Threat Analysis and Protection (STAP) engine provide a verdict (good or bad) of such files almost instantly.
Xcitium AEP can quickly identify and eliminate malware (including ransomware) across endpoints without affecting end-user experience. Try Xcitium Advanced Endpoint Protection today!
For more information on Xcitium Advanced Endpoint Protection, contact us at EnterpriseSolutions@comodo.com or +1 888-256-2608.
Frequently Asked Questions
How does ransomware spread?
Ransomware spreads through phishing, malicious downloads, stolen credentials, vulnerable systems, remote access, and lateral movement across networks.
Can ransomware spread over a network?
Yes. Attackers can use compromised accounts and connected services to move between networked systems.
Can ransomware spread through Wi-Fi?
Not simply because devices share Wi-Fi, but vulnerable or accessible devices on the same network can be at risk.
Can ransomware spread through email?
Yes. Phishing emails can deliver malicious attachments, links, or credential-stealing pages.
Can ransomware spread through USB?
Some malware can spread through removable media, so unknown USB devices should not be trusted.
Can ransomware spread to cloud storage?
Yes. Encrypted synchronized files or compromised cloud accounts can affect cloud-stored data.
Can ransomware infect backups?
Accessible backups can be encrypted, deleted, or otherwise disrupted during an attack.
Does ransomware spread automatically?
Some variants can, but many modern ransomware attacks involve attackers manually moving through networks.
Can ransomware spread from one PC to another?
Yes. Network access, stolen credentials, vulnerabilities, and shared resources can enable an attack to expand.
How do you stop ransomware from spreading?
Isolate affected systems, restrict compromised accounts, segment networks, and follow your incident response plan.
