Ransomware is a type of malicious software that encrypts files on a victim’s computer and demands payment in order to decrypt them. Ransomware has become an increasingly common cyberthreat in recent years. Fortunately, there are free tools available that may help victims recover encrypted files without paying the ransom.
How does ransomware infect computers?
Ransomware typically spreads through phishing emails containing malicious links or attachments. If a user clicks on a malicious link or opens an infected attachment, the ransomware downloads and installs itself on the victim’s machine. It then encrypts files and displays a ransom note demanding payment, often in cryptocurrency such as Bitcoin. The ransom note provides instructions for how to pay the ransom and obtain a decryption key.
What files does ransomware target?
Ransomware often targets files that are most valuable to victims. This typically includes:
- Documents – Word files, Excel spreadsheets, PDFs
- Images – JPEGs, PNGs, GIFs
- Videos
- Database files
- Backups
By encrypting important files and making them inaccessible, ransomware aims to coerce victims into paying the ransom to regain access. Even personal files like family photos and videos may be encrypted.
What are the risks of paying the ransom?
There are several risks to paying a ransomware ransom:
- There is no guarantee files will be decrypted – Attackers may simply take the money and never provide the decryption key.
- It encourages more attacks – Paying the ransom shows attackers that ransomware is profitable.
- Loss of funds – Ransoms may range from a few hundred to thousands of dollars.
- Data may be stolen – Attackers may exfiltrate copies of data before encrypting.
For these reasons, security experts recommend not paying the ransom. Instead, victims should use backups and free recovery tools when possible.
What is a free ransomware recovery tool?
A free ransomware recovery tool is a piece of software designed to help victims recover encrypted files without paying the ransom. These tools work by exploiting weaknesses in ransomware variants to restore files to their original, unencrypted state. There are several free options available:
Emsisoft Decrypter
The Emsisoft Decrypter contains decryption capabilities for over 140 ransomware families. It scans a compromised system to determine which strain is present, then uses the appropriate decryption algorithm to restore files. Emsisoft updates the tool regularly as new ransomware variants emerge.
Avast Decryption Tools
Avast offers decryption tools for ransomware families like AES_NI, Apocalypse, BadBlock, and over a dozen others. The tools are updated frequently to cover new ransomware strains. Its simple interface makes it easy for victims to decrypt files.
Kaspersky Anti-Ransomware Tool
Kaspersky’s ransomware recovery tool can block and reverse encryption for some forms of ransomware. It’s designed to detect and terminate ransomware processes, suspend encryption, and roll back any changes made during an attack.
Trend Micro Ransomware File Decryptor
Trend Micro’s decryptor currently works to unlock files after attacks by ransomware families like AES_VAWTRN and Stampado. It can recover files affected on local drives, removable drives, and network shares.
Bitdefender Decryptors
Bitdefender offers decryption utilities designed to restore files after ransomware attacks without paying the ransom. Specific variants covered include GandCrab, IEncrypt, DMALocker, and Rannoh. Bitdefender periodically updates its tools.
Who develops these free recovery tools?
Most free ransomware recovery tools are developed by cybersecurity companies that specialize in malware research and protection. These include firms like:
- Emsisoft
- Avast
- Kaspersky
- Trend Micro
- Bitdefender
These companies have teams of malware analysts and security experts that dissect ransomware strains to understand how they work. They then use this knowledge to create decryption tools that can reverse the encryption process and restore files.
Government agencies also sometimes develop and release free decryption tools based on their own research into ransomware.
How do the recovery tools work?
Free ransomware decryption tools work in a few different ways:
- Exploit flaws in encryption – Tools may take advantage of weaknesses like reuse of encryption keys that allow decryption.
- Unlock ransomware – Some tools are designed to unlock the ransomware itself to access decryption keys.
- Brute force decryption keys – Trying millions of possible decryption keys to find the correct one.
In many cases, security researchers are able to break the encryption used by ransomware through cryptanalysis of the algorithm. They can then incorporate the decrypted keys into tools.
What are the steps to use a ransomware recovery tool?
Using a ransomware recovery tool involves a straightforward process:
- Disconnect infected device – Disconnect the infected device from any network to prevent ransomware from spreading.
- Identify ransomware – Determine the ransomware variant based on the ransom note and attack details.
- Download decryptor – Obtain the appropriate decryption tool for the ransomware identified.
- Run decryptor – Follow prompts to scan the device and decrypt files. May take time.
- Restore files – Once decrypted, files can be retrieved and backed up.
Running the decryption tool correctly is key, so following usage instructions closely is important. However, the process is much simpler than paying the ransom.
How effective are free ransomware recovery tools?
The effectiveness of ransomware decryption tools varies:
- Highly effective for some strains – Tools exist to reliably decrypt certain ransomware variants like GandCrab.
- Partial decryption – Some tools can only decrypt a portion of files.
- Ineffective for newer strains – Developing new tools takes time after new ransomware emerges.
So the ability to use a tool for recovery depends on the ransomware. Older, more widely distributed ransomware tends to have more decryption options. Newer or less common strains are more challenging. Still, security firms add new decryption capabilities continuously.
What are the limitations of using a ransomware recovery tool?
Some drawbacks and limitations include:
- No tool exists for newer strains – Developing tools takes time after new ransomware emerges.
- Partial decryption only – Some tools may only decrypt some file types or a portion of files.
- Files may be corrupted – Decryption failures may lead to corrupted files.
- Permanent data loss – Heavily encrypted files may still be unrecoverable.
Additionally, ransomware decryption can be a lengthy process depending on the number of files affected. And there’s no guarantee a tool will work – it depends on the nature of the attack and ransomware variant.
Can files be recovered without paying the ransom?
It’s sometimes possible to recover encrypted files without paying the ransom in certain scenarios:
- Ransomware decryption tools – These tools can decrypt files for many ransomware strains.
- Backups – Restoring from clean, uninfected backups can retrieve original files.
- Shadow copies – If ransomware doesn’t delete Volume Shadow Copies, they can restore files.
- Cloud storage – Files saved in cloud storage may be retrievable following an attack.
However, newer strains of ransomware often take steps to make these traditional recovery methods ineffective. Still, free decryptors are updated continuously, making them an option worth pursuing.
Should ransom be paid if tools are ineffective?
Paying the ransom should only be a last resort. Even if free tools are ineffective, companies should exhaust every other option first:
- Consult security firms – Many firms are willing to help recover files for free in ransomware attacks.
- Leverage backups – Offline, immutable backups may provide clean file copies.
- Wipe and remediate – In some cases, wiping systems and restoring data from scratch is preferable.
- Negotiate ransom – It may be possible to negotiate a lower ransom, but risks remain.
Paying the ransom fundamentally supports criminal activity and should only even be considered if all other avenues fail and the encrypted data is absolutely critical.
How can individuals and businesses avoid ransomware attacks?
Steps to reduce the risk of ransomware include:
- Training employees – Educate staff on ransomware red flags like phishing.
- Limiting privileges – Only provide minimum privileges needed to reduce ability to spread.
- Applying patches – Keep software updated to close vulnerabilities.
- Using antivirus – Antivirus with anti-ransomware capabilities helps detect malware.
- Filtering email – Block dangerous file types and scan attachments.
- Backing up regularly – Maintain regular backups offline and immutable.
- Segmenting networks – Isolate and segment networks to limit lateral movement.
Taking a layered approach to security makes ransomware compromise more difficult. But backups and recovery tools serve as the last line of defense if other measures fail.
Conclusion
Free ransomware recovery tools provide victims with a way to potentially decrypt files after a ransomware attack, avoiding payment of the ransom. Leading security firms like Emsisoft, Avast, and Kaspersky develop these tools by analyzing ransomware to uncover weaknesses in the encryption algorithms used. While not foolproof, decryption tools are frequently updated and can be highly effective against many ransomware strains. However, preventing ransomware using comprehensive security measures is always preferable to relying on recovery tools after compromise occurs.