What are the signs of ransomware?

Ransomware is a type of malware that encrypts files on a device and demands payment in order to decrypt them. Detecting a ransomware infection early is crucial to avoid serious disruption to individuals or organizations. Here are some key signs to watch out for that may indicate ransomware activity.

Inability to Access Files

One of the first and most obvious signs of a potential ransomware attack is finding that you are suddenly unable to open files that you know exist on your computer or network drives. When ransomware infects a system, it will encrypt files, which renders them inaccessible without the decryption key. Users may encounter error messages when trying to open files or find that files have been renamed with strange new file extensions.

ransomware

Some examples of what you may see include:

  • Being unable to open documents, pictures, databases, or other common files
  • File extensions changed to something like .locky or .crypt
  • “Error” messages or ransom notes appearing when trying to open files
  • Files having red “X”s or locks on their icons
  • Certain files increasing dramatically in size

If you notice any of these issues affecting files across your system, it’s a telltale sign of ransomware encryption at work.

Strange New Files Appear

In addition to encrypting existing files, ransomware infections will also often deposit new, strange files onto your system. These may include:

  • Ransom notes or text files with payment instructions
  • Files with random names and no extensions
  • Unfamiliar executable files (.exe or .dll files)

Ransomware will typically leave ransom notes or text files containing payment demands and instructions for restoring your files. These may be deposited in every directory that contains encrypted files.

Executable files could indicate malicious files deposited by the ransomware or tools used to encrypt your system. Unfamiliar .exe or .dll files should always be viewed as suspicious.

Noises From Your Speakers or Webcam

Certain types of ransomware exhibit worm-like behavior, attempting to spread rapidly across other computers and networks. Sometimes ransomware incidents are accompanied by:

  • Loud, repeated audio playing from your speakers
  • Flashing screens or display output from your webcam

These activities are attempts to capture your attention so you see the ransom note or notice the attack unfolding. If your speakers or webcam seem to activate inexplicably, especially blaring noises or ransomware messages, your system may be infected.

Application Crashes or Unusual Behavior

Ransomware that targets specific business applications may cause them to suddenly crash, display errors, or behave erratically. For example, ransomware could target a database server, causing it to freeze or display access issues. Email servers could be affected in similar ways.

Suspicious application crashes or behavior, especially across multiple computers or servers, may indicate ransomware disrupting processes and services to encrypt important data files.

Ransom Notes or Warnings

In some cases, ransomware will create pop-up windows displaying ransom payment instructions or warnings. These may include:

  • “Your files are encrypted!” messages with payment demands
  • Fake warnings from law enforcement asking you to pay fines
  • Threats that your files will be deleted if you don’t pay

Any messages suggesting your files are hostage or demanding some kind of payment should be treated as probable ransomware. Avoid paying anything or following unsolicited instructions.

Can’t Access Certain Websites

Some ransomware will block access to specific external IP addresses and websites to prevent you from accessing tools that could recover your files. If certain websites abruptly become unavailable across your network, it may be due to malicious DNS overrides by ransomware.

Slow Computer or Network

Ransomware encrypting your files in the background can significantly slow down your computer’s speed. The encryption process puts extra load on your CPU and hard drive. Network bandwidth can also be strained as ransomware communicates with command servers.

Sluggish system performance or unusually slow network connections may be signs of ransomware infecting files and communicating over the network.

Disabled Security Software

Many ransomware variants act quickly to disable installed security software, such as antivirus programs or endpoint detection and response (EDR) systems. This prevents these tools from detecting the ransomware before it has time to encrypt your files.

If your antivirus suddenly disables itself or stops running for no reason, it could be due to malicious disabling by ransomware that has infected your system.

Unexpected Reboots or Crashes

Some ransomware infections may cause system crashes, error messages, or unexpected restarts to evade detection. This can happen as ransomware encrypts key system files, disrupting normal computer processes.

Any program crashes, random reboots, or error messages, especially those referencing problems reaching system files, could potentially indicate ransomware is damaging critical data on your computer.

What are the sources of ransomware infections?

Ransomware frequently spreads through these common infection vectors:

Malicious Email Attachments

Many ransomware attacks begin with phishing emails containing infected file attachments. The attachments may appear as normal files like PDFs or Microsoft Office documents, but they contain executables or scripts that install the ransomware. Opening or downloading these attachments infects your system.

Infected Websites

Hackers can infect websites with ransomware downloaders, redirect scripts, and browser-based exploits. Browsing such sites, especially risky sites like torrent hosts and adult content, may trigger drive-by ransomware downloads.

Software Vulnerabilities

Unpatched software vulnerabilities can allow ransomware to gain access to systems. Keeping all software up-to-date with the latest security patches is critical to avoid known exploit vectors.

Network Attacks

Ransomware variants like WannaCry and NotPetya spread as worms through networks to infect large numbers of systems. Maintaining secure network segmentation and monitoring traffic patterns can help defend against such self-propagating ransomware attacks.

External Drives

USB drives or external hard disks infected with ransomware are a common source of infection. Always securely scan external media on a separate system before transferring files to your computer.

Remote Desktop Access

Unsecured remote desktop (RDP) connections offer easy access for ransomware attackers. Keeping your RDP port blocked or protected with strong passwords is important to prevent external infection.

How can you prevent and recover from ransomware?

Here are some key precautions and tips for defending against ransomware threats:

Maintain backups

Regularly backing up your important data makes it easy to restore your files if they are encrypted. Store backups offline or immutable to prevent ransomware accessing them.

Enable security software

Run endpoint protection software like antivirus and EDR solutions. Keep them up-to-date and properly configured to scan for threats.

Patch promptly

Apply software patches and updates as soon as they become available to eliminate security flaws that ransomware relies on.

Restrict file permissions

Only allow users or applications access to the specific files and directories they need. Limiting permissions can slow down ransomware encrypting large file stores.

Block unnecessary ports

Close internet ports like RDP that are commonly targeted by external ransomware attacks, or put them behind VPNs.

Isolate critical data

Use separate partitions or drives for storing sensitive data. Keep offline backups in case your primary data gets encrypted.

Educate employees

Train staff in cybersecurity best practices, like identifying phishing emails. Empower employees to flag suspicious activity.

Monitor network traffic

Analyze patterns to catch ransomware communications. Detecting malware behavior lets you respond before major damage is done.

Disable macros

Block Office macro execution to protect against document-based attacks. Only enable macros when absolutely required.

Don’t pay ransoms

There is no guarantee criminals will restore your files. Paying ransoms funds and encourages more attacks.

Conclusion

Acting quickly when ransomware is detected gives you the best chance of recovering encrypted files and preventing widespread damage. Understanding the common warning signs like system lockouts, ransom notes, and unusual application behavior allows you to rapidly identify and contain infections.

Implementing strong prevention measures such as comprehensive backups, security software, and patch management is crucial for minimizing disruptions caused by ransomware. With the right blend of user education, monitoring, and defensive solutions, organizations can manage the risks posed by ransomware threats.