Geek's Advice

GCYI ransomware is a computer virus that attempts to extort you

GCYI ransomware is the latest malicious file-encrypting virus to emerge from the notorious STOP/DJVU ransomware family. This ransomware encrypts every file detected in a computer it infiltrates and adds .gcyi extension to original filenames. For example, file 1.jpg as initially held in the computer will be renamed 1.jpg.gcyi and the same process will be repeated on all other data. The malware drops ransom notes known as _readme.txt in all computer folders. These notes are notifications sent by the cybercriminals. They inform the computer user about the situation and why the criminals expect the user to pay a certain money mount as ransom in exchange for GCYI decryption tool.

The attackers will point out that GCYI ransomware virus has rendered the entire database of the infected computer useless through encryption and use of solid key. In essence, all documents, pictures, various data etc. contained in the computer would no longer be useful to the owner except he pays ransom to those behind the attack so they could supply decryption tools that would restore them back to normal. Also included in the _readme.txt ransom notes are two emails the victim would be expected to use in communicating with them i.e. support@sysmail.ch and helprestoremanager@airmail.cc.

The note will also contain decryption service prices and the conditions attached with it. They will inform the victim that payment must be made ASAP if they intend to benefit from their ransom fee slash whereby they could pay just 50% of the fee if such payment can be made within the next 72 hours i.e. 3 days. This would bring the cost down to $490 but failure to comply within the “grace period” means that only the maximum fee of $980 would be acceptable.

However, if/when the victim contacts them, he will be giving more conditions, one of which is that payment can only be made through the purchase of cryptocurrency that is equivalent to the ransom fee and transferring it to a wallet address that would be provided by them. The obvious reason why they do this is to avert any possible chance of being tracked down using the payment medium. Still, with cryptocurrency, such fears won’t be there since it provides anonymity.

To encourage the victim to pay without hesitation, they may suggest that one of the encrypted files should be sent to them for test decryption but would also warn that such file must not contain any information that could perceive as important to the victim.

Our in-house cybersecurity experts advise that victims should follow the FBI’s guidelines in situations like this, and it categorically says NO to ransom payment. There are various reasons why paying is strongly discouraged, and the main ones are:

• There is no guarantee you will recover your encrypted files even after paying the ransom.
• Paying ransom makes huge sums of money available to cybercriminals which encourages them in their criminal activities.
• More funds at their disposal would enable them to employ more hands and enhance their capacity to victimize more people.

The ransomware is equally known to drop other information-stealing Trojans like VIDAR and AZORULT on the already compromised computer, which they use in trying to steal other important information such as banking details, cryptocurrency wallets, passwords and software login credentials etc. When such sensitive information gets into the wrong hands, it can result in further criminal activities such as stealing or blackmail.

If you’re infected with malware under discussion, we advise you to remove GCYI ransomware virus without any delay. This can be done effectively with the use of strong antivirus software that should be activated while the infected computer is set up in Safe Mode with Networking option. You can make use of any virus of your choice but always ensure they’re genuine. However, if you’re not sure about which brand of antivirus to use, we recommend INTEGO Antivirus. You can also consider downloading RESTORO as repair software to restore your virus damaged Windows OS files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware distribution methods to be wary of

The most common method of spreading any variant of STOP/DJVU ransomware virus, including GCYI virus is through making downloads on malicious online torrents. The cybercriminals usually attach malware to pirated software copies which they upload to online torrents platforms and the virus will become triggered when unsuspecting users download such contents to their computers. The so-called “cracks” and key generators are nothing but baits used by cybercriminals to prey on their victims. Information gathered from victims of ransomware indicate that certain pirated software contents are often used as listed below:

• Adobe Photoshop;
• Adobe Illustrator;
• Tenorshare 4ukey;
• AutoCad;
• Opera browser;
• Corel Draw;
• VMware Workstation;
• Cubase;
• Fifa 20;
• Various AV software;
• League of Legends;
• Internet Download Manager;
• KMSPico (illegal Windows activation tool).

For those that usually visit online torrents platforms, it is high time this habit is dropped for good. It is a lot safer, more convenient, and cheaper in the long run to download software content needs through the officially recognized channels than using malicious online torrents. Whatever fee that is required by the original content developers is always far less than what cybercriminals will demand from those that would eventually become victims of ransomware, and neither would there be any risk of losing vital/sensitive data. Moreover, using such illegal channels is considered a criminal offence and is punishable by law. Therefore, it is advisable for users of software to always pay the requisite fee and download their software needs from the original content developers or their affiliated agents.

Another method used by cybercriminals to spread ransomware is through malicious email attachments whereby they would create believable messages that would be accompanied with attachments formatted with DOCX, XLS or PDF. They work with these particular formats because they enable macro functions and JavaScript which can be used to spread and trigger payloads in diverse random computers.

The biggest challenge is how to differentiate a genuine email from fake ones sent by cybercriminals considering that such emails are now made to appear so much like real ones. They usually pretend to be acquaintances or popular brands such as Amazon, UPS, eBay etc. and would attach files with inciting names like Invoice, Tracking Details, Order Summary among others just to compel the target victim to open them. Alternatively, they sometimes apply email spoofing techniques just to hide the actual sender’s address. Whatever gimmick they use, you should avoid opening emails/attachments that appear odd unless you’re convinced they’re genuine.

Nevertheless, STOP/DJVU ransomware victims should not visit any website that claim to provide decryption solutions because more often than not they are fraudulent. At the moment, only DiskTuna and Emsisoft have proven capability of decrypting/repairing files and you can check here for more details about them. The real intention of those behind such dubious sites is to further scam the victims by spreading other ransomware versions like ZORAB.

More detailed information about the virus

This part provides more detailed information about the technical aspects of the ransomware attack and how much the victim’s computer was affected. The first thing the malware does following a ransomware attack is to establish build.exe and build2.exe executables and also winupdate.exe, which acts as a fake Windows update screen. After that, it will connect with https[:]//api.2ip.ua/geo.json before saving the outcome on geo.json file. The malware begins information gathering about the computer, especially its geolocation, time zone, zip code, longitude and latitude, as well as another file that would contain hardware details, software list, and active processes on information.txt. Here is an example showing geo.json file as shown in the display below.

Contents of information.txt file are shown down below.

Making use of the geolocation data, the malware will profile it against a list of countries they designated as encrypted-exempted and they are: Russian Federation, Ukraine, Belarus, Syria, Armenia, Tajikistan Uzbekistan, Kazachstan, and Kyrgyzstan. If it happens that such computer is located in any of these countries, it will stop any further action. However, if it scales this geolocation hurdle, the malware will then extract online encryption key from their server and would merge it with the victim’s ID before saving it in the bowsakkdestx.txt file and to the PersonalID.txt file. Provided in the image below are examples of these files.

If for any reason the malware fails to extract any online encryption key, it will promptly opt for the use of a hardcoded offline key instead. The difference is that online encryption key is unique to every victim, unlike offline key that is uniform to all victims of the same variant of ransomware. You can easily tell if an encryption type is offline if your personal ID has t1 characters appearing at the end of it, and the implication is that .gcyi files can possibly be decrypted going forward. More information about this is provided below.

At this point, the ransomware then commences total data encryption process by scanning the folders and encrypting them with Salsa20 which would also be locked using RSA-2048 encryption key. After modifying a file, the virus also adds .gcyi extension to its original filename.

Displayed here is a screenshot of _readme.txt ransom note which is dropped in several computer folders.

The virus will also delete Volume Shadow Copies by using the command prompt task as displayed below:

^{vssadmin.exe Delete Shadows /All /Quiet}

In completing the encryption process, the malware will add certain domains to the Windows HOSTS file and also map them to the localhost IP, thereby effectively preventing the victim from getting any form of help from those online sites. Any attempt to access those platforms will result in DNS_PROBE_FINISHED_NXDOMAIN error message appearing on the computer display.

Remove GCYI Ransomware Virus and also Recover Your Files

The first thing a victim of ransomware is expected to do is to set up their computer in Safe Mode with Networking booting option, before running antivirus software to ensure the virus is completely removed. Our team approves INTEGO Antivirus. Additionally, you may want to download RESTORO to identify and repair virus damage on Windows OS files. Once that is done, the following steps should be followed through accordingly:

• Get in touch with any relevant local government agency vested with the authority to inspect such issues.
• Make use of any available data backups to restore your lost files.
• Look for ways files encrypted by STOP/DJVU ransomware variants can be decrypted/repaired.
• Immediately change all passwords that were associated with the compromised computer.

OUR GEEKS RECOMMEND

Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:

STEP 1. REMOVE AUTOMATICALLY WITH ROBUST ANTIVIRUS

REMOVE & PROTECT WITH INTEGO

Get INTEGO ANTIVIRUS for Windows to remove ransomware, Trojans, adware and other spyware and malware variants and protect your PC and network drives 24/7.. This VB100-certified security software uses state-of-art technology to provide protection against ransomware, Zero-Day attacks and advanced threats, Intego Web Shield blocks dangerous websites, phishing attacks, malicious downloads and installation of potentially unwanted programs.

Use INTEGO Antivirus to remove detected threats from your computer.

Read full review here.

STEP 2. REPAIR VIRUS DAMAGE TO YOUR COMPUTER

DOWNLOAD RESTORO

RESTORO provides a free scan that helps to identify hardware, security and stability issues and presents a comprehensive report which can help you to locate and fix detected issues manually. It is a great PC repair software to use after you remove malware with professional antivirus. The full version of software will fix detected issues and repair virus damage caused to your Windows OS files automatically.

RESTORO uses AVIRA scanning engine to detect existing spyware and malware. If any are found, the software will eliminate them.

Read full review here.

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Norbert Webb

Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.