This article provides a detailed removal guide to the new variant of GlobeImposter ransomware virus and recovery alternatives for corrupted .astra files.
The .astra file virus is a malware of ransomware type that corrupts target data stored on the infected machines and extorts ransom from victims. The threat appears to be a new iteration of the GlobeImposter ransomware that employs massive attack campaigns generally against European and American users. After two versions that have been released last week – .725 and ..726, security researchers reported another one that renames encrypted files with the malicious file extension .astra and drops a ransom note file called here_your_files!.html
|Name||.astra File Virus|
|Short Description||Globeimposter ransomware encrypts files on your computer, appends the extension .astra to them and displays a ransom message afterward.|
|Symptoms||Your valuable files become inaccessible and are renamed with the extension .astra. For their decryption a ransom note appears on the PC screen and demands a ransom payment.|
|Distribution Method||Spam Emails, Email Attachments|
|Detection Tool|| See If Your System Has Been Affected by .astra File Virus |
Malware Removal Tool
|User Experience||Join Our Forum to Discuss .astra File Virus.|
|Data Recovery Tool||Windows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive.|
.astra File Virus – Spread Techniques
The authors of .astra file virus are using spam email campaigns as a preferred spread technique of the ransomware payloads. The emails usually pose as legitimate sources and provide file attachments that need to be downloaded and started on the PC. It is known that GlobeImposter ransomware code may be hidden in one of the following file types:
→.docx, .exe, .js, .wsf, .hta, .vbs, .htm
The files can be zipped in an archive file and once you double click them after the unzipping they cause the ransomware infection. Exceptions are the .docx files that mainly contain the ransomware payload as an embedded content that should be enabled to trigger the infection.
.astra File Virus – More Information
Once the malicious file is executed it connects a hacked domain controlled by hackers, downloads .astra file virus and runs it. Additionally, the threat drops more malicious files and creates processes to support its effective system infection. Some of the processes set the Windows system to avoid sleep mode so the ransomware can encrypt the target files. Others are used for adding the malicious payload in the start group of Windows apps through the registry editor. For the purpose .astra file virus may add new registry value strings in the following keys:
This allows its payloads to be executed automatically whenever the system starts.
To prevent file restore from the Shadow Volume copies, it runs the command line “vssadmin.exe Delete Shadows /All /Quiet” and removes all shadows.
Finally, the ransomware generates and drops an HTML file in all folders that contain encrypted files. The file is called here_your_files!.html. It informs that particular files have been encrypted and provides instructions on how to pay to get them back. Below you can see the beginning of the .astra file virus ransom message:
All your files have been encrypted!
All your files have been encrypted due to a security problem with your PC. lf you want to restore them, write us in TOR Browser, hxxp://cr7icbfqm64hixta.onion, Install the TOR Browser from this link http.//torproject.org ,in body of your message write your ID
You have to pay for decryption Bitcoins. The price depends on how fast you write to us. After payment we will send you the decryption tool that will decrypt all your files.
Free decryption as guarantee
Before paying you can send us up to 1 file for free decryption. The total size of files must be less than 1 Mb (non archived), and files should not contain valuable information. (databases, backups, large excel sheets, etc.)
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click ‘Buy bitcoins’, and select the seller by payment method and price.
Also you can find other places to buy Bicoins and beginners guide here:
• Do not rename encrypted files.
• Do not try to decrypt your data using third party software, it may cause permanent data loss…
It is not clear what the demanded ransom amount is, however it should be transferred in Bitcoins. To prevent further malware attacks it is NOT recommended contacting criminals and under no circumstances paying the ransom. There is no guarantee that cyber criminals will be strict enough to send back the decryption key even after the ransom payment.
.astra File Virus – Encryption Process
The ransomware first scans files in all of the partitions on the infected machine. It then encrypts almost each file that potentially contains valuable information – documents, images, videos, music, text files, databases, archives, projects, etc. It reads the file and if it is not part of its exclusion list then encrypts the file content using the RSA algorithm overwriting the original content with encrypted content. Afterward, it appends .astra to each encrypted file name to identify that the file has been encrypted. Since GlobeImposter uses an RSA-2048 cipher algorithm to encrypt files, it’s very hard to be cracked. The good news is that alternative data recovery solutions are available and may help to get back some .astra files. Check step “Restore files encrypted by .astra File Virus” from the ransomware removal instructions below.
Remove .astra File Virus and Restore Data
The .astra file virus should be removed as soon as possible from the infected computer because its presence endangers your new files and the security of the whole system. Beware that it has a complex code that has modified various system settings, values, and processes in order to ensure its stable attendance on the PC. For the best removal results, security experts recommend the assistance of professional anti-malware tool.
After the removal process, it is good to back up all encrypted .astra files and then try to recover some of them as it is pointed at step “Restore files encrypted by .astra File Virus” below.