Menu
Don’t run JS email attachments: ​they​ can carry potent ransomware

Don’t run JS email attachments: ​they​ can carry potent ransomware

A new ransomware program called RAA is entirely written in JavaScript

Attackers are infecting computers with a new ransomware program called RAA that's written entirely in JavaScript and locks users' files by using strong encryption.

Most malware programs for Windows are written in compiled programming languages like C or C++ and take the form of portable executable files such as .exe or .dll. Others use command-line scripting such as Windows batch or PowerShell.

It's rare to see client-side malware written in Web-based languages such as JavaScript, which are primarily intended to be interpreted by browsers. Yet the Windows Script Host, a service built into Windows, can natively execute .js and other scripting files out of the box.

Attackers have taken to this technique in recent months, with Microsoft warning about a spike in malicious email attachments containing JavaScript files back in April. Last month, security researchers from ESET warned of a wave of spam that distributes the Locky ransomware through .js attachments.

In both of those cases the JavaScript files were used as malware downloaders -- scripts designed to download and install a traditional malware program. In the case of RAA, however, the whole ransomware is written in JavaScript.

According to experts from tech support forum BleepingComputer.com, RAA relies on CryptoJS, a legitimate JavaScript library, to implement its encryption routine. The implementation appears to be solid, using the AES-256 encryption algorithm.

Once it encrypts a file, RAA adds a .locked extension to its original name. The ransomware targets the following file types: .doc, .xls, .rtf, .pdf, .dbf, .jpg, .dwg, .cdr, .psd, .cd, .mdb, .png, .lcd, .zip, .rar and .csv.

"At this point there is no way to decrypt the files for free," said Lawrence Abrams, the founder of BleepingComputer.com, in a blog post.

The RAA infections reported so far by users display the ransom note in Russian, but even if the threat only targets Russian-speaking users for now, it's only a matter of time until it's distributed more broadly and localized for other languages.

It is very uncommon for people to send legitimate applications written in JavaScript via email, so users should avoid opening this type of file, even if it's enclosed in a .zip archive. There are few reasons for .js files to exist outside websites and Web browsers in the first place.

Follow Us

Join the New Zealand Reseller News newsletter!

Error: Please check your email address.

Slideshows

Top 50 defining moments of the New Zealand channel in 2016

Top 50 defining moments of the New Zealand channel in 2016

Reseller News looks back on a tumultuous 12 months for the New Zealand channel, assessing the fallout from a year of sizeable industry change. Whether it be local or global mergers and acquisitions, distribution deals or job changes, the channel that started the year differs somewhat to the one set to finish it - Reseller News assesses the key moments that made 2016.​

Top 50 defining moments of the New Zealand channel in 2016
​Hewlett Packard Enterprise honours high achieving NZ channel

​Hewlett Packard Enterprise honours high achieving NZ channel

Hewlett Packard Enterprise honoured its top performing Kiwi partners at the second running of its HPE Partner Awards in New Zealand, held at a glitzy ceremony in Auckland. Recognising excellence across eight categories - from distributors to resellers - the tech giant celebrated its first year as a standalone company, following its official split from HP in 2015.

​Hewlett Packard Enterprise honours high achieving NZ channel
Nutanix treats channel partners to Christmas cruise

Nutanix treats channel partners to Christmas cruise

Nutanix recently took to the seas for a Christmas Cruise around Sydney Harbour with its Australia and New Zealand staff, customers and partners to celebrate a stellar year for the vendor. With the sun out, they were all smiles and mingled over drinks and food.

Nutanix treats channel partners to Christmas cruise
Show Comments