What is CryptoLocker ransomware

What is ransomware?

Ransomware is a type of malicious software (malware) that encrypts files or locks computer systems, holding them hostage until a ransom is paid to the attacker. It is designed to extort money from individuals, organizations, or businesses by denying access to their own data or systems.
When a computer or network falls victim to ransomware, the malware encrypts the files, rendering them inaccessible to the user. The attacker behind the ransomware then demands a ransom, typically in the form of cryptocurrency like Bitcoin, in exchange for providing the decryption key or restoring access to the system.
Ransomware is commonly propagated through various means, including phishing emails, malicious attachments, or by exploiting vulnerabilities in software or operating systems. Once the ransomware gains entry into a system, it initiates the process of encrypting files, rendering them inaccessible to the victim. Subsequently, a ransom note is displayed, providing instructions on how to make the payment and obtain the decryption key to restore access to the compromised data.
Paying the ransom does not guarantee that the attacker will provide the decryption key or unlock the system, and it may even encourage further attacks. Additionally, complying with the demands of ransomware attacks can support criminal activities and contribute to the perpetuation of such threats.

What is CryptoLocker Ransomware?

CryptoLocker, identified in 2013, is a notorious type of ransomware that wreaked havoc in the digital landscape. This malicious software operates by encrypting files on an infected computer, rendering them inaccessible to the victim.
Once CryptoLocker infiltrates a computer, it initiates a systematic scan across local drives and network shares, targeting specific file types like documents, images, videos, and more. Employing robust encryption algorithms, it locks these files, rendering them inaccessible to the user without the corresponding decryption key. To make its presence known, CryptoLocker often displays a message on the victim’s screen, conveying details about the encryption process and outlining instructions on how to submit the demanded ransom in order to obtain the necessary decryption key.
CryptoLocker usually demands payment in a form of cryptocurrency, such as Bitcoin, as it offers a degree of anonymity for the cybercriminals. The ransom amount can vary, but it is often set relatively high to increase the likelihood of payment. Victims are typically given a deadline to pay the ransom, with the threat that failure to comply will result in the permanent loss of the decryption key and their files.

History of CryptoLocker Ransomware

CryptoLocker ransomware made its debut in September 2013, swiftly earning a reputation as one of the most devastating and financially lucrative strains of ransomware known thus far. Here’s a brief timeline of its history:

  1. September 2013: CryptoLocker is first observed in the wild. It primarily spreads through email attachments, disguised as legitimate files, often in the form of fake invoices, delivery notices, or voicemail messages.
  2. Infections and Encryption: Once a system is infected, CryptoLocker starts encrypting files on local and network drives using strong encryption algorithms like RSA. It targets a wide range of file types, including documents, images, videos, and more. The encrypted files become inaccessible without the unique decryption key.
  3. Ransom Demand: After encryption, CryptoLocker displays a ransom note informing the victim about the encryption and demanding a ransom payment, typically in Bitcoin or other cryptocurrencies. The ransom amount varied, often ranging from hundreds to thousands of dollars.
  4. Payment and Decryption: Victims were given a limited time window, typically 72 hours, to pay the ransom. If the payment was not made within the deadline, the decryption key was permanently deleted, making file recovery practically impossible.
  5. Disruption and Takedowns: CryptoLocker garnered significant attention due to its widespread impact. It infected numerous individuals, businesses, and organizations worldwide, causing significant data loss and financial damage. Efforts by cybersecurity researchers and law enforcement led to the takedown of command-and-control servers associated with CryptoLocker in May 2014, significantly reducing its prevalence.
  6. Evolution and Copycats: The success of CryptoLocker inspired the creation of various copycat ransomware strains that adopted similar techniques and demanded ransoms. Some notable successors include CryptoWall, Locky, Cerber, and SamSam, which continued to evolve and pose threats in the following years.

While the original CryptoLocker was largely neutralized, the ransomware threat landscape has continued to evolve, with new variants and families constantly emerging. Ransomware attacks remain a significant cybersecurity concern, emphasizing the importance of robust security measures, regular backups, and user awareness to prevent and mitigate such threats.

What to do if you think you have CryptoLocker Ransomware?

If you suspect that your computer or network has been infected with CryptoLocker ransomware or any other ransomware strain, it’s important to take immediate action to minimize the damage and protect your data. Here are the steps you should follow:

  1. Isolate the Infected System: Disconnect the infected computer from the network to prevent the ransomware from spreading to other connected devices or shared resources. This can help contain the impact and protect unaffected systems.
  2. Do Not Pay the Ransom: It is strongly advised not to pay the ransom. There is no guarantee that the cybercriminals will provide the decryption key, and paying the ransom only encourages further criminal activity. It is best to explore alternative options to recover your files.
  3. Report the Incident: Contact your local law enforcement agency or a dedicated cybersecurity incident response team and provide them with all the relevant information about the ransomware attack. Reporting the incident can help authorities track and apprehend the criminals and contribute to overall efforts to combat cybercrime.
  4. Consult with Security Professionals: Seek assistance from cybersecurity experts or an incident response team who have experience dealing with ransomware. They can provide guidance and help assess the situation, analyze the ransomware, and determine possible recovery options.
  5. Remove the Ransomware: Once you have sought professional advice, follow their instructions to safely remove the ransomware from your system. Use reputable antivirus or anti-malware software to scan and clean your computer.
  6. Restore from Backups: If you have regular backups of your files stored on external devices or in the cloud, you can restore your data after ensuring that the ransomware has been completely removed. Be cautious not to restore any infected files.
  7. Explore Decryption Tools: In some cases, cybersecurity researchers and organizations may release decryption tools for certain ransomware strains. Check reputable sources, such as the No More Ransom project (www.nomoreransom.org), to see if there are any decryption tools available for the specific ransomware affecting you.
  8. Strengthen Security Measures: After recovering from a ransomware attack, review and enhance your security measures. Update your operating system and software to the latest versions, install reputable antivirus software, enable firewalls, and regularly patch known vulnerabilities. Educate yourself and your employees about safe online practices, such as avoiding suspicious emails and attachments.

Remember, prevention is key to protecting against ransomware attacks. Regularly back up your important files, use strong and unique passwords, exercise caution when opening email attachments or clicking on suspicious links, and keep your security software up to date.

How to protect yourself and avoid infection by CryptoLocker Ransomware

To protect yourself and avoid infection by CryptoLocker ransomware or any other ransomware strain, it’s essential to adopt good cybersecurity practices. Here are some preventive measures you can take:

  1. Keep Your Software Updated: Keeping your operating system, antivirus software, web browsers, and other applications regularly updated with the latest security patches is crucial in safeguarding your computer against ransomware and other malware threats. Outdated software often contains vulnerabilities that can be exploited by attackers. By staying up to date, you ensure that these vulnerabilities are patched, reducing the risk of falling victim to ransomware attacks.
  2. Use Reliable Security Software: Install reputable antivirus or anti-malware software on your computer and keep it up to date. Use real-time scanning and enable automatic updates to ensure continuous protection against emerging threats.
  3. Exercise Caution with Email Attachments and Links: Be vigilant while opening email attachments or clicking on links, especially if they are from unknown or suspicious sources. Do not open attachments or click on links that seem unexpected, even if they appear to come from known contacts. Be particularly cautious with file types commonly associated with malware, such as executable files (.exe) or files with macros enabled.
  4. Beware of Phishing Attempts: Ransomware often spreads through phishing emails, which attempt to deceive users into revealing sensitive information or downloading malicious attachments. Be cautious of emails asking for personal information or containing urgent requests. Verify the legitimacy of emails before taking any actions.
  5. Backup Your Data Regularly: Regularly backup your important files to external storage devices or secure cloud services. Ensure that backups are stored offline or in a separate network location not directly accessible from your main system. This way, if you fall victim to ransomware, you can restore your files without paying the ransom.
  6. Enable File Extensions: Enable the visibility of file extensions on your operating system. This allows you to easily identify suspicious file types that may be used by ransomware, such as an executable file masquerading as a PDF or Word document.
  7. Be Cautious of Remote Desktop Services: If you use Remote Desktop Protocol (RDP) to connect to your computer remotely, ensure that you use strong, unique passwords and consider enabling additional security measures like multi-factor authentication (MFA). Ransomware attackers may attempt to exploit weak RDP credentials to gain unauthorized access.
  8. Educate Yourself and Employees: Stay informed about the latest ransomware threats and educate yourself and your employees about safe online practices. Train employees to recognize phishing attempts, avoid suspicious websites, and be cautious of downloading or executing files from unknown sources.
  9. Use Firewall Protection: Enabling a firewall on your computer or network is an important step in protecting against ransomware and other malicious threats. A firewall acts as a protective barrier, monitoring and controlling incoming and outgoing network traffic. It helps to block unauthorized access attempts and filters out potentially harmful or suspicious traffic.

By implementing these preventive measures, practicing good digital hygiene, and staying vigilant, you can significantly reduce the risk of falling victim to ransomware attacks like CryptoLocker.


In conclusion, CryptoLocker ransomware is a malicious software that encrypts files on infected computers and demands a ransom for their decryption. It first appeared in 2013 and caused widespread damage and financial losses. While the original CryptoLocker strain was largely neutralized, ransomware threats continue to evolve with new variants and families emerging.
If you suspect that your computer is infected with CryptoLocker or any other ransomware, it is crucial to take immediate action. Isolate the infected system, report the incident to law enforcement, and seek assistance from cybersecurity professionals. It is strongly advised not to pay the ransom, as there is no guarantee of file recovery.
To protect yourself and avoid ransomware infections, maintain up-to-date software, use reliable security software, exercise caution with email attachments and links, backup your data regularly, enable file extensions, be cautious of remote desktop services, educate yourself and your employees about safe online practices, and use firewall protection.
By taking these preventive measures and staying proactive in your cybersecurity practices, you can greatly reduce the chances of becoming a victim of ransomware attacks and safeguard your valuable data. Stay well-informed about the latest threats, remain vigilant, and make security a top priority in order to maintain a safe digital environment.

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