Zepto ransomware - How to remove

Zepto ransomware is a new version of Locky ransomware released on the 27th of June, 2016. Just as its predecessor, it uses asymmetric (RSA-2048 and AES-128) encryption algorithm. But there are some peculiarities of this new variant.

About Zepto Ransomware

Zepto ransomware is written in JS (Javascript). Once, it gets into your system, Windows runs wsscript.exe module and executes the script. No code verifications are carried out or security scannings performed. The .js executable connects to C&C (Command&Control) server to download the payload of the ransomware. And, once it is downloaded, the encoding virus scans the computer’s system and locks the data. It targets the files with the following extensions:

.3gp, .7z, .apk, .avi, .bmp, .cdr, .cer, .chm, conf, .css, .csv, .dat, .db, .dbf, .djvu, .dbx, .docm, ,doc, .epub, .docx .fb2, .flv, .gif, .gz, .iso .ibooks,.jpeg, .jpg, .key, .mdb .md2, .mdf, .mht, .mobi .mhtm, .mkv, .mov, .mp3, .mp4, .mpg .mpeg, .pict, .pdf, .pps, .pkg, .png, .ppt .pptx, .ppsx, .psd, .rar, .rtf, .scr, .swf, .sav, .tiff, .tif, .tbl, .torrent, .txt, .vsd,.wmv, .xls, .xlsx, .xps, .xml, .ckp, zip, .java, .py, .asm, .c, .cpp, .cs, .js, .php, .dacpac, .rbw, .rb, .mrg, .dcx, .db3, .sql, .sqlite3, .sqlite, .sqlitedb, .psd, .psp, .pdb, .dxf, .dwg, .drw, .casb, .ccp, .cal, .cmx, .cr2.

As you can see, most documents, media files, code, and data that are stored as conventional file types are attacked by Zepto and converted to ciphertext by its encryption algorithm. Then, the files become unusable.

Dangers of Zepto ransomware and the ways they can be mitigated:

Files targeted by Zepto for encryption	Documents Audio, video, image files
The encryption method	Asymmetric encryption Secure No free decrypter has been released
The symptoms	Ransom note in _HELP_instructions.html and in the desktop background Files renamed to “024BCD33-41D1-ACD3-3EEA-84083E322DFA.zepto”
Zepto ransomware removal	Scan with anti-malware (Spyhunter) to remove the infection Use System Restore Restore the locked files from a backup Use data recovery to get back deleted files

 

Zepto cryptomalware renames the encrypted files with an enormous filename. An example of a name of an encrypted file – 024BCD33-41D1-ACD3-3EEA-84083E322DFA.zepto. The victim’s ID would be the first 16 characters of the filename, that is 024BCD3341D1ACD3. This encrypting virus also changes the type of the files, which then becomes ZEPTO Files. On an interesting note, this encoder overwrites files and deletes the original versions. _HELP_instructions.bmp file, containing the ransom note, replaces the desktop wallpaper. _HELP_instructions.html files are dropped in every folder of encrypted files and on the victim’s desktop. The note reads as follows:

!!! IMPORTANT INFORMATION !!!

All of your files are encrypted with RSA-2048 and AES-128 ciphers.
More information about the RSA and AES can be found here:
[links to wikipedia]

Decrypting of your files is only possible with the private key and decrypt program, which is on our secret server.
To receive your private key follow one of the link
[Tor Web links given]

If all of this addresses are not available, follow these steps:
[the instructions on how to download and install Tor Browser are given]

!!! Your personal identification ID: A2E4B02F73265D55 !!!

This ransom note is very similar to the one dropped by Diablo6, which is another version of Locky.

How is Zepto Ransomware Distributed?

Zepto virus is a trojan virus. It is spread via infected .js files, which look like .doc or .pdf files, and are added to e-mails and sent to victims. These e-mails fall into the spam folder of the e-mail accounts of the targeted users. They are disguised as important documents issued by legitimate companies. These could be PayPal, FedEx, your local institutions such as Customs, etc. Phishing methods are numerous and varied, including tax refund requests, this PDF-based scam, one targeting Google Docs, and many others. Once the attachment is opened, all the evils are released.

Indeed, many trusted and mundane file types can be hijacked to deliver malware. Phishing emails only need to convince you to open the attached file, and they can be very convincing.

Malicious spam might not seem like a very sophisticated method of infecting computers with malware but it is one of the most effective ones. Few people scan every file they download before opening it and few have real-time protection enabled by their anti-malware.

How to Decrypt Files Encrypted by Zepto Ransomware?

Zepto ransomware virus, just like the Locky ransomware, is still undecryptable. Most probably, if the decryptor for Locky is developed, it will suit Zepto as well. But, for now, the only solution to retrieve your data is to apply data recovery tools such as software by Kaspersky Lab, R-Studio, PhotoRec, etc. It seems that this encrypter, similarly to Locky, deletes the Shadow Volume Copies. So Shadow Volume Service, even if utilized, will be of no use. By the way, if you stored copies of your files in some external storage devices or services, you are saved. If not, the only solution remains the data recovery with professional tools. It would be wise of you to make use of some hard drive or, for instance, Cloud Service in the future. File recovery is not the only thing you must do.

Paying the ransom is not advised. Though not disclosed in the note, the size of the ransom is the same as of Locky’s ransomware – 0.5 BTC (Bitcoins) amounting to 319.86 USD at the present moment. Not a huge pile of money, but still it would be a pity to lose it.

Especially since the chance that you can still recover the files is almost nonexistent. When dealing with ransomware, paying the ransom only restores the files some of the time. Even if files are restored, some of them might not be recreated correctly — technical issues come up frequently when dealing with crypto extortionists.

Even more importantly, you have to remove the ransomware. Employ Spyhunter or other automatic malware removal tools. They will scan the computer’s system so that no virus or its leftovers are left. Manual instructions on how to eliminate Zepto virus and possibly recover your files are provided below.

Automatic Malware removal tools

How to recover Zepto ransomware encrypted files and remove the virus

Step 1. Restore system into last known good state using system restore

1. Reboot your computer to Safe Mode with Command Prompt:

for Windows 7 / Vista/ XP

• Start → Shutdown → Restart → OK.
• Press F8 key repeatedly until Advanced Boot Options window appears.
• Choose Safe Mode with Command Prompt.

for Windows 8 / 10

• Press Power at Windows login screen. Then press and hold Shift key and click Restart.
• Choose Troubleshoot → Advanced Options → Startup Settings and click Restart.
• When it loads, select Enable Safe Mode with Command Prompt from the list of Startup Settings.

 

2.Restore System files and settings.

• When Command Prompt mode loads, enter cd restore and press Enter.
• Then enter rstrui.exe and press Enter again.
• Click “Next” in the windows that appeared.
• Select one of the Restore Points that are available before Zepto virus has infiltrated to your system and then click “Next”.
• To start System restore click “Yes”.

 

Step 2. Complete removal of Zepto ransomware

After restoring your system, it is recommended to scan your computer with an anti-malware program, like Spyhunter and remove all malicious files related to Zepto virus. You can check other tools here.  

Step 3. Restore Zepto ransomware affected files using Shadow Volume Copies

If you do not use System Restore option on your operating system, there is a chance to use shadow copy snapshots. They store copies of your files that point of time when the system restore snapshot was created. Usually Zepto virus tries to delete all possible Shadow Volume Copies, so this methods may not work on all computers. However, it may fail to do so. Shadow Volume Copies are only available with Windows XP Service Pack 2, Windows Vista, Windows 7, and Windows 8. There are two ways to retrieve your files via Shadow Volume Copy. You can do it using native Windows Previous Versions or via Shadow Explorer. a) Native Windows Previous Versions Right-click on an encrypted file and select Properties → Previous versions tab. Now you will see all available copies of that particular file and the time when it was stored in a Shadow Volume Copy. Choose the version of the file you want to retrieve and click Copy if you want to save it to some directory of your own, or Restore if you want to replace existing, encrypted file. If you want to see the content of file first, just click Open.

b) Shadow Explorer It is a program that can be found online for free. You can download either a full or a portable version of Shadow Explorer. Open the program. On the left top corner select the drive where the file you are looking for is a stored. You will see all folders on that drive. To retrieve a whole folder, right-click on it and select “Export”. Then choose where you want it to be stored.

Step 4. Use Data Recovery programs to recover Zepto ransomware encrypted files

There are several data recovery programs that might recover encrypted files as well. This does not work in all cases but you can try this:

• We suggest using another PC and connect the infected hard drive as slave. It is still possible to do this on infected PC though.
• Download a data recovery program.
• Install and scan for recently deleted files.

Note: In many cases it is impossible to restore data files affected by modern ransomware. Thus I recommend using decent cloud backup software as precaution. We recommend checking out Carbonite, BackBlaze, CrashPlan or Mozy Home.