Palo Alto Networks' Unit 42 researchers discovered a new and previously undocumented Remote Access Tool (RAT) last month and then blogged about it. They say that they found almost 50 instances of it in more than 2,200 attack sessions they monitored within the first month it was available for sale. The report goes into the RAT manager/builder, client malware, as well as profiling the 18-year-old Swedish threat actor they assert is behind it.

Using the handles Speccy and Rafiki, the author posted a link to the RAT sales site on some dark web forums in the beginning of September. He thoughtfully posted a setup video for it as well. This hands-on sales approach may be indicating the rise of personalized, "artisanal" malware efforts. Taking a commodity product (the RAT) and adding value by overlaying additional buyer services is similar to what craft breweries do. It may serve as a justification for higher product prices, as well.

Speccy on his sales site offers licenses to his RAT at a relatively high price when compared to other commodity RATs. $49 gets a 31-day license, and there are discount plans of $117 for 93 days, and $438 for one year. Payment is made in major cryptocurrencies.\r\nThe features of the RAT are enumerated on the site too, but boil down to "you can do anything you want" to the target/victim. Blackremote (that's the name of the RAT) uses the third-party "CodeVEST" licensing system, which is also to be found on underground forums.

When it is unpacked after purchase, the manager/builder installs a 9MB main executable BLACK-RC.EXE, a pair of resource libraries, and a resource directory with a pair of .wav files. The builder can customize the client to the form needed by the purchaser.

Both the builder and client that will be on the victim machine are heavily protected, using more than one obfuscator (Agile.NET, Babel .NET, Crypto Obfuscator, Dotfuscator, Goliath.NET, SmartAssembly, Spices.Net, Xenocode).

The command and control path for the RAT was well known to Unit42. The same C2 has been observed by them as being used by the same actor in over 50 Netwire, Nanocore, Quasar and Remcos commodity RAT samples that date back to early 2018.

The researchers say that they have outed the perpetrator. In the blog they note that, "Unit 42 has fully identified this actor; we will not share his identity here, but we have ensured that the correct authorities have been advised. The longer this is sold, not only the more samples of this RAT will be built and spread, but also the opportunity for other actors to crack this RAT and distribute it indiscriminately. It is important to identify and interdict the sale of such malware as early as possible to prevent its proliferation, which enables a large population of unsophisticated threat actors."

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.