CipherLocker is a file-encrypting ransomware variant that targets Windows systems, locking users out of their personal files and demanding payment for decryption. Unlike some ransomware families that have known decryption tools available, CipherLocker typically uses strong encryption algorithms that make file recovery without the attackers' private key extremely difficult. Victims discover their documents, photos, databases, and other valuable files have been scrambled and renamed, often with a custom extension appended to the original filename.
This threat represents a serious risk to both home users and small businesses, as it can encrypt files on local drives, network shares, and connected backup devices if those backups are mounted at the time of infection. The ransom demands typically range from several hundred to several thousand dollars, usually payable in cryptocurrency, with no guarantee that paying will result in file recovery.
Threat Profile
| Attribute | Details |
|---|---|
| Threat Type | Ransomware (Crypto-ransomware) |
| Family | CipherLocker (distinct from CryptoLocker) |
| Platform | Windows (all versions vulnerable) |
| Encryption Method | AES or RSA encryption (variants differ) |
| File Extensions Targeted | Documents, images, databases, archives, backups (200+ file types) |
| Ransom Note Filename | Varies by variant (commonly HOW_TO_DECRYPT.txt, READ_ME.html, or similar) |
| Distribution Vectors | Malicious email attachments, exploit kits, software cracks, Remote Desktop compromise |
| Persistence Mechanism | Run keys, scheduled tasks (typical for ransomware family) |
| Network Behavior | Command-and-control communication for key exchange, Tor-based payment portals |
| Data Exfiltration | Not typical for this family (focused on encryption) |
| Removal Difficulty | Moderate (removing the malware itself), but file recovery extremely difficult without decryption key |
| Free Decryption Tool | Not currently available for most variants |
How It Spreads
CipherLocker reaches victims through multiple attack vectors, with the most common being phishing emails containing malicious attachments. These emails are often disguised as invoices, shipping notifications, resumes, or urgent business correspondence designed to trick recipients into opening an attached document or executable file. The attachments may be disguised with double extensions (like "invoice.pdf.exe") or embedded macros in Office documents that download and execute the ransomware payload when enabled.
Beyond email, CipherLocker has been distributed through compromised websites hosting exploit kits that target unpatched browser vulnerabilities, malicious advertisements (malvertising) on legitimate sites, and bundled with pirated software or key generators downloaded from file-sharing networks. In some cases targeting businesses, attackers have gained access through poorly secured Remote Desktop Protocol (RDP) connections, using brute-force attacks or stolen credentials to manually install the ransomware on company networks.
Common distribution methods include:
- Email attachments disguised as business documents (Word/Excel with macros, PDFs with embedded payloads, ZIP archives containing executables)
- Links in phishing emails directing to download sites that serve the ransomware instead of the promised content
- Drive-by downloads from compromised or malicious websites exploiting browser or plugin vulnerabilities
- Software cracks, keygens, and pirated applications from torrent sites or warez forums
- Exploit kits (automated attack frameworks) targeting outdated Flash, Java, or browser components
- RDP brute-force attacks against internet-facing systems with weak passwords
- Supply chain compromise through infected installers for legitimate-looking applications
What It Does On Your Machine
Once executed, CipherLocker begins by establishing persistence on the infected system, ensuring it can complete its encryption process even if the computer is restarted. The malware typically copies itself to a location in the user's application data folder or a subfolder with a randomly generated name, then creates registry entries or scheduled tasks to maintain execution. During this initial phase, it may also attempt to disable Windows security features, delete volume shadow copies (the restore points that could be used for file recovery), and terminate processes associated with backup software or database applications to ensure those files can be encrypted.
The encryption phase targets specific file types across all accessible drives, including local hard drives, mapped network shares, and any connected removable media like USB drives or external hard drives. CipherLocker scans for hundreds of file extensions associated with documents, spreadsheets, databases, images, videos, archives, and other user data. It encrypts each file using a strong cryptographic algorithm and typically renames them with a custom extension or appends an extension to the original filename. The malware uses asymmetric encryption, where a public key (embedded in the malware) encrypts the files, but only the attackers possess the corresponding private key needed for decryption.
After encryption completes, CipherLocker displays a ransom note either as a text file dropped in every folder containing encrypted files, a window that appears on startup, or by changing the desktop wallpaper to display payment instructions. The note informs victims that their files have been encrypted and provides instructions for paying the ransom, typically through cryptocurrency like Bitcoin to an address unique to that victim. The message usually includes threats that the decryption key will be destroyed after a deadline (creating artificial urgency) and warnings against attempting file recovery or removal, which the attackers claim will make decryption impossible.
Throughout this process, CipherLocker typically communicates with command-and-control servers operated by the attackers, sending information about the infected system and receiving the encryption keys or configuration updates. Some variants operate entirely offline with embedded keys, while others require network connectivity to function. The malware may also collect basic system information and send it to the attackers, though CipherLocker variants generally focus on encryption rather than extensive data theft.
Manual Removal — Step by Step
Isolate the Infected System Immediately
Disconnect the computer from all networks by unplugging the Ethernet cable and disabling Wi-Fi. Physically disconnect any external drives, USB sticks, or network-attached storage devices to prevent the ransomware from spreading to those locations. If you're on a business network, alert your IT department or shut down the router to isolate other machines. Do not reconnect until the infection is completely removed and you've verified no malware remains.
Boot Into Safe Mode with Networking
Restart the computer and repeatedly press F8 (or Shift+F8 on Windows 10/11) before the Windows logo appears to access the Advanced Boot Options menu. Select "Safe Mode with Networking" to start Windows with minimal drivers loaded, which prevents most malware from running automatically. On Windows 10/11, you may need to hold Shift while clicking Restart, then navigate through Troubleshoot > Advanced Options > Startup Settings > Restart, and press F5 for Safe Mode with Networking once the options appear.
Identify and Terminate Malicious Processes
Press Ctrl+Shift+Esc to open Task Manager, then look for suspicious processes with random names or unusual resource usage, particularly those running from %APPDATA% or %TEMP% locations. Right-click any suspected CipherLocker process and select "Open File Location" to identify where the executable resides, then right-click and choose "End Task" to terminate it. Document the file paths you find—you'll need them for the next steps. Be cautious not to terminate legitimate Windows processes; when in doubt, research the process name online before ending it.
Remove Persistence Mechanisms
Press Windows+R, type "regedit" and press Enter to open the Registry Editor. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run and HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run, looking for entries with suspicious names or paths that match the executable location you identified. Right-click and delete any malicious entries. Next, press Windows+R, type "taskschd.msc" to open Task Scheduler, and review the task library for any suspicious scheduled tasks (particularly those with random names or running executables from %APPDATA%). Right-click and delete any that correspond to the ransomware.
Delete the Ransomware Executable and Associated Files
Using File Explorer, navigate to the folder where you found the CipherLocker executable (typically in %APPDATA%, %LOCALAPPDATA%, or %TEMP%). Delete the entire folder containing the ransomware binary and any associated files. You may need to enable "Show Hidden Files" in File Explorer's View options. Also search for and delete any ransom notes (files like HOW_TO_DECRYPT.txt or READ_ME.html) found throughout your system, though these are harmless once the executable is removed.
Scan with Reputable Anti-Malware Tools
Download and install Malwarebytes Free (from malwarebytes.com) or another reputable anti-malware scanner while still in Safe Mode with Networking. Run a full system scan to detect any remaining components, droppers, or associated malware that may have been installed alongside CipherLocker. Follow the software's prompts to quarantine or remove all detected threats. Consider running a second scan with a different tool (such as Emsisoft Emergency Kit or Kaspersky Virus Removal Tool) for confirmation, as no single scanner catches everything.
Check for Available Decryption Tools
Visit the No More Ransom Project website (nomoreransom.org) and search for CipherLocker decryption tools. While most CipherLocker variants do not have free decryptors available, new ones are occasionally released as security researchers break the encryption or recover private keys from seized command servers. If a decryptor exists for your specific variant, download it only from official sources and follow the provided instructions carefully. Do not trust "decryption services" found through web searches, as many are scams.
Attempt File Recovery from Backups or Shadow Copies
If you have external backups that were not connected during the infection, connect them now and restore your files. Check whether Windows Shadow Copies survived by right-clicking an encrypted file, selecting "Properties," then the "Previous Versions" tab—if any restore points exist, you may be able to recover files from before the encryption. Tools like Shadow Explorer can help browse shadow copies more easily. This step has limited success because CipherLocker typically deletes shadow copies, but it's worth checking before considering more drastic measures.
Change All Passwords from a Clean Device
Since ransomware is sometimes delivered alongside password-stealing malware or keyloggers, assume your credentials may be compromised. Using a different, confirmed-clean computer or smartphone, change passwords for all important accounts: email, banking, work systems, cloud storage, and social media. Enable two-factor authentication wherever possible to add an additional layer of protection. Do not change passwords from the infected computer until you're certain all malware has been removed.
Reboot Normally and Verify System Cleanliness
Restart the computer in normal mode and carefully monitor its behavior for any signs of remaining infection: unexpected slowdowns, network activity when idle, new files appearing in temp folders, or security software being disabled. Run another quick scan with your anti-malware tool, check that all persistence mechanisms remain removed, and verify that Windows Defender or your primary antivirus is running and updated. If encrypted files are not recoverable and backups don't exist, preserve those files on an external drive in case a decryption tool becomes available in the future, then consider whether a clean Windows reinstall is the safest path forward.
Prevention
- Maintain Regular Offline Backups: Follow the 3-2-1 backup rule (three copies of data, on two different media types, with one copy offsite/offline). Keep at least one backup on an external drive that's disconnected from your computer except during scheduled backup operations. Cloud backups alone are insufficient, as ransomware can encrypt synced files.
- Keep All Software Updated: Enable automatic updates for Windows, browsers, and all applications, especially Adobe Reader, Java, and Microsoft Office. Most ransomware distribution relies on exploiting known vulnerabilities in outdated software. Remove or disable plugins like Flash and Java if you don't actively use them.
- Exercise Email Caution: Never open unexpected attachments or click links in emails, even if they appear to come from known contacts (email addresses can be spoofed). Be especially wary of invoices, receipts, resumes, and shipping notifications you weren't expecting. Verify suspicious messages by contacting the supposed sender through a different communication channel.
- Disable Macros by Default: Configure Microsoft Office to disable macros in documents from the internet. Most legitimate businesses do not send documents requiring macro execution, and this setting blocks a primary ransomware infection method. If you must open a document with macros, carefully verify its source first.
- Use Reliable Security Software: Install reputable antivirus/anti-malware software with real-time protection and keep it updated. Enable Windows Defender if you don't use third-party security software. While no solution is perfect, good security software catches many threats before they execute.
- Restrict User Privileges: Operate under a standard user account for daily activities rather than an administrator account. Ransomware executed by a standard user has more limited access to system files and other user profiles, potentially containing the damage.
- Enable Controlled Folder Access: On Windows 10/11, enable Controlled Folder Access in Windows Security settings, which prevents unauthorized applications from modifying files in protected folders like Documents, Pictures, and Desktop. This feature specifically defends against ransomware encryption attempts.
- Secure Remote Access: If you use Remote Desktop Protocol, ensure it's protected with strong passwords, account lockout policies after failed attempts, and ideally accessible only through a VPN. Better yet, disable RDP entirely if you don't need it, or restrict it to specific IP addresses through your firewall.
Bring It In
Ransomware removal and recovery is complex work that requires careful attention to detail. While the steps above can help technically-inclined users remove the CipherLocker infection itself, the real challenge is often file recovery—and that's where professional help makes the difference. At Computer Repair Roswell, we have specialized tools and techniques for maximizing file recovery chances, including advanced shadow copy recovery methods, connections to decryption research communities, and experience assessing which files might be recoverable. More importantly, we can verify that your system is truly clean and advise on backup strategies to prevent re-infection.
Don't let ransomware hold your files hostage or leave you uncertain whether your system is truly safe. Bring your computer to our shop in Roswell, Georgia, or give us a call. We'll assess your situation honestly, explain your recovery options, and handle the technical work of removing the infection and restoring your system to safe operation. If your business has been affected, we can also help implement the security measures that will protect you going forward. Ransomware is serious, but you don't have to face it alone—that's what we're here for.