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Beware of .svg file virus on Facebook

Beware of .svg file virus on Facebook

SVG stands for “Scalable Vector Graphics”, which is a fairly popular XML-based image format that allows for extensive animation effects. One of the main pros of .svg extension files for graphics designers is that these objects can be handled via commonplace text editors, just like XML text files. The virtues being obvious, cybercriminals have come up with a way to exploit these images for ransomware distribution.

Numerous users have been reporting a Facebook spam campaign where a suspicious photo in SVG format is received over the built-in instant messenger out of the blue. The filename tends to follow a pattern like this: Photo_[random_digits].svg. The likelihood of a recipient downloading this image is fairly high, because it comes from one of the person’s actual Facebook contacts. The explanation of this trick has to do with the fact that a friend got hit by the same infection, which now attempts to hand over the malicious code to as many people as possible. According to analysts’ verdicts, the contagion propagating this way is Nemucod, an infamous malware downloader. The danger is therefore twofold. First off, the malady gains access to a targeted user’s social networking account. Secondly, it tries to install a nasty ransomware called Locky that scours the PC for personal files and encrypts them.

Malicious SVG file sent over Facebook IM chat

Here’s what the attack chain looks like. When a user clicks to download the booby-trapped photo, they unknowingly trigger offending JavaScript code that’s covertly built into the file’s XML content. This event ends up opening a Chrome window and redirects the victim to a website that bears a strong resemblance to YouTube but is actually a bogus page. The site looks like it hosts some video, but a popup alert will state that the content won’t play unless the user adds a Chrome extension called “One” or “Ubo”. This pseudo add-on is misleadingly described as a codec extension to watch the above-mentioned video.

Rogue Chrome extension installation prompt

Interestingly enough, the popup says that the extension can “read and change all your data on the websites you visit,” which is true. Nonetheless, some people do install this bad item and thus expose their machines to a severe breach. Once the rogue browser helper object obtains these privileges, it accesses the victim’s Facebook account and starts sending the contagious .svg file to all contacts in a stealthy fashion. This is a crafty, self-contained loop that amplifies the attack surface without direct involvement of the threat actors.

The notoriety of Nemucod revolves around its ability to install other malware behind the scenes. Unfortunately, that’s exactly what happens here. The malicious kit downloads and executes the Locky ransomware on the infected system. The latest version of this ransom Trojan will encode the user’s important files using AES and RSA ciphers, scramble filenames beyond recognition, append the .aesir extension to all of these entries, and extort 0.5 Bitcoin for decryption. All in all, the Facebook spam campaign involving SVG files poses one of the most intricate methods to disseminate crypto ransomware. An additional issue is that the Nemucod infection will be active in the background, and who knows what other payloads it may drag into the PC and execute further on.

SVG file virus automatic removal

Extermination of this ransomware can be efficiently accomplished with reliable security software. Sticking to the automatic cleanup technique ensures that all components of the infection get thoroughly wiped from your system.

1. Download recommended security utility and get your PC checked for malicious objects by selecting the Start Computer Scan option

2. The scan will come up with a list of detected items. Click Fix Threats to get the virus and related infections removed from your system. Completing this phase of the cleanup process is most likely to lead to complete eradication of the plague proper. Now you are facing a bigger challenge – try and get your data back.

Methods to restore files encrypted by SVG file virus

Workaround 1: Use file recovery software

It’s important to know that the Locky ransomware creates copies of your files and encrypts them. In the meanwhile, the original files get deleted. There are applications out there that can restore the removed data. You can utilize tools like Data Recovery Pro for this purpose. The newest version of the ransomware under consideration tends to apply secure deletion with several overwrites, but in any case this method is worth a try.

Workaround 2: Make use of backups

First and foremost, this is a great way of recovering your files. It’s only applicable, though, if you have been backing up the information stored on your machine. If so, do not fail to benefit from your forethought.

Workaround 3: Use Shadow Volume Copies

In case you didn’t know, the operating system creates so-called Shadow Volume Copies of every file as long as System Restore is activated on the computer. As restore points are created at specified intervals, snapshots of files as they appear at that moment are generated as well. Be advised this method does not ensure the recovery of the latest versions of your files. It’s certainly worth a shot though. This workflow is doable in two ways: manually and through the use of an automatic solution. Let’s first take a look at the manual process.

  • Use the Previous Versions feature

    The Windows OS provides a built-in option of recovering previous versions of files. It can also be applied to folders. Just right-click on a file or folder, select Properties and hit the tab named Previous Versions. Within the versions area, you will see the list of backed up copies of the file / folder, with the respective time and date indication. Select the latest entry and click Copy if you wish to restore the object to a new location that you can specify. If you click the Restore button, the item will be restored to its original location.
    Previous Versions

  • Apply Shadow Explorer tool

    This workflow allows restoring previous versions of files and folders in an automatic mode rather than by hand. To do this, download and install the Shadow Explorer application. After you run it, select the drive name and the date that the file versions were created. Right-click on the folder or file of interest and select the Export option. Then simply specify the location to which the data should be restored.
    ShadowExplorer

Verify whether the .SVG file virus has been completely removed

Again, malware removal alone does not lead to the decryption of your personal files. The data restore methods highlighted above may or may not do the trick, but the ransomware itself does not belong inside your computer. Incidentally, it often comes with other malware, which is why it definitely makes sense to repeatedly scan the system with automatic security software in order to make sure no harmful remnants of this virus and associated threats are left inside Windows Registry and other locations.

Posted in: KnowledgeBase

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