Nemty

Nemty is ransomware with an unusually complex encryption algorithm. This malware encrypts user files and demands money so that they can be unlocked again. It may be connected to other famous ransomware, but we don’t know for sure.

Type
Ransomware
Origin
ex-USSR territory
First seen
1 August, 2019
Last seen
21 October, 2021
Also known as
NEMTY PROJECT
Global rank
42
Week rank
38
Month rank
41
IOCs
199

Nemty, also known as NEMTY PROJECT is a ransomware-type of malware. A virus that puts encryption on all files that are stored on infected machines and only allows to restore them if victims pay a certain ransom amount.

Nemty has surfaced not so long ago. It was first observed in the wild in August 2019. Due to some similarities in the code and behavior, researchers think that Nemty might be related to GandCrab and Sodinokibi, though direct correlation hasn’t been proved. In any case, it is safe to assume that this is very advanced malware.

Additionally, the malware’s code apparently includes an affiliate ID which may indicate that Nemty is available as a Ransomware as a Service. If this information is correct Nemty has the potential to become a very widespread malware due to its easy availability.

General description of Nemty ransomware

Nemty ransomware is being actively upgraded by its creators. In fact, several versions of the virus have already been released and nothing suggests that this development should stop anytime soon.

Among other upgrades, threat actors employed a very strong encryption algorithm. It is actually so strong that no malware before Nemty has used anything similar. The RSA-8192 used here is 8192-bit encryption which is considered to be an overkill for use in malware. Even though this encryption protocol makes data decryption more difficult it also presents its own complications. For example, it causes longer encryption and key generation times and only encrypts 1024 bytes at a time.

Despite this, researchers have been able to create decryptors that work with versions 1.4, 1.5 and 1.6 of the malware, for example, the Avast Nemty decryption tool. This means that victims that have been attacked by the version of the malware mentioned above can restore their information without having to pay the ransom to the attackers.

Without the decryptors like the Avast Nemty tool, victims would have to pay a ransom of about $1000 equivalent in Bitcoin to the attackers. The ransom can be paid through a payment portal that is hosted using the TOR network. And if not paid on time, the amount is doubled to a $2000 equivalent.

We don’t know for sure who the people behind Nemty are. The malware has code that checks if the victim is from one of the following countries: Russia, Belarus, Kazakhstan, Tajikistan, or Ukraine.

However, victims from the countries mentioned above can still get attacked by the ransomware. This is strange since usually, viruses that check for the origins of victims terminate execution to avoid getting attention from local law enforcement structures.

In the case of Nemty, users from all over the world are in danger of being infected.

However, there are other interesting oddities in the code that point to a ex-USSR origin of the virus. The code contains a link to a similar picture that was linked in GandCrab’s code. Except, this time it contains on an overlay of the Russian president’s portrait. There are other weird things to be found in the code of this malware. For example, if you dig deep enough you will find a direct message to cybersecurity professionals telling them to, well, “mind their own business” in a less polite form.

More evidence suggesting the x-USSR origin of the malware creators is that the payment page is in the Russian language. Maybe the creators are in fact Russian or they are trying to plant a false lead and mislead researchers.

Malware analysis of Nemty ransomware

A video recorded in the ANY.RUN malware hunting service allows us to take a look at the execution of this malware in action.

nemty's ransom note

Figure 1: Nemty's ransom note

text report of the Nemty ransomware analysis

Figure 2: Shows a customizable text report generated by the ANY.RUN malware analysis service which allows diving deeper into the details of the Nemty execution process.

Nemty execution process

The execution process of the Nemty ransomware is relatively typical for this type of malware. After the executable file makes its way into an infected system and runs, the main malicious activity begins. Like many other ransomware families, Nemty deletes shadow copy files. It also stops and kills processes from the hardcoded list. The malware creates a text file with a ransom note in every folder with encrypted files.

The interesting thing is that Nemty, as well as Sodinokibi, creates a registry key in which it stores values such as a public key and a file extension for encrypted files.

Nemty Distribution

Initially, Nemty was using RIG and Radio EK exploit kits for distribution purposes. In addition to that, malware authors employed spam email campaigns to distribute the virus primarily in Korea and China. These two countries are where the bulk of all Nemty infections is happening.

However, with the newer versions of the malware coming out, threat actors started using new distribution methods. Possibly they were trying to expand the reach of the malware and gain the ability to infect more victims.

One of such methods is a fake PayPal website that promises to save money with an unusually high cashback. The website is designed to look identical to the genuine PayPal and prompts users to download a file called “cashback.exe”. Although unsuspecting victims might think that they are downloading a PayPal app, in reality, they are installing and executing the Nemty ransomware.

In addition, later versions of the malware are delivered using the Trik botnet. Apparently, the authors of Nemty have partnered up with people behind Trik to increase their range.

How to detect Nemty using ANY.RUN?

To determine whether the sample under review is Nemty or not, you can take a look at the changes that it made in the registry. To do so, open "Advanced details of process" of the malicious process and look at the "Registry changes" tab in the "Events" section. If a process has created values with the names "cfg", "pbkey" or "fid" into the key HKEY_CURRENT_USER\Software\NEMTY, you can be sure that the given sample is Nemty.

changes in registry made by nemty ransomware

Figure 3: Changes in registry made by Nemty ransomware

Conclusion

The constant evolution of distribution methods, as well as regular updates, prove that this malware is at a stage of active development. First seen in 2019, Nemty is a young threat that already shows signs of sophisticated malware.

Coupled with the potential use of the Ransomware as a Service business model that makes this malware available to many threat actors around the globe, these factors demand that this threat is not taken lightly.

One of the primary dangers of this Ransomware lies in the delivery techniques chosen by the attackers. While mail spam helps to reach millions of potential victims easily, heavy use of exploit kits allows attackers to control every step of the infection.

Thus, it is especially important that security researchers can evaluate this ransomware and continue developing countermeasures and encryptors, like the Avast Nemty. One more tool that can help in this pursuit is the ANY.RUN malware hunting service that will allow studying samples of Nemty in a controlled and safe environment.

IOCs

IP addresses
172.67.75.166
104.26.4.15
104.26.5.15
50.19.104.221
50.16.235.219
50.16.246.238
23.21.168.151
23.21.136.132
54.235.176.177
50.19.252.36
54.225.169.250
54.225.66.103
23.21.42.25
54.225.215.180
23.21.42.216
174.129.255.253
204.236.231.159
184.73.165.106
50.19.115.217
174.129.223.190
Hashes
0a14d4313ded36716d9de16b8487ac91b0dcf6a77c9f0c21531916c31a0a5ee9
5078a0940abc31a7fa271483ac345044a91a0e21c517bceb85091cd3fca310f7
a9e866898f343aaab28063977c13dec133ab7dd5c8f155cf90540b71371413ac
b893f726f30f3a63bc899383f724ab7b8e8e4d674db40efa5972d23cb8ed1a8a
4799d051f0e40b15ec67593ea838df901613018d26b612d6d2447431323d4a01
068575719283c1e33abb8530340d7ac0b4d44b15da1ee0877c03537216df3001
3d852ca618763ced2e280f0c0079e804935b70dcd4adc3912c2e2b3965e196c4
97451dec59c7af7adb53126486841c275f76c932973af8eeeaada49728a75016
0c18068dab291fcdd5a9aa94fb6cb07b8aeec1e4ecbab3746c3b0586e7bbd692
664b45ba61cf7e17012b22374c0c2a52a2e661e9c8c1c40982137c910095179a
708922215acc1ddbe35a9549afce408aaa0aa74caa78feca96150e755ebf7b98
b01054d750aaa982359bee75707847f30df668135ca139e25b142e18f8cf2f51
613c390d6b3b792d6bf0765e97719ac4278741abcebdd03d9fe394c8a46a841c
518394d105b9f9f1c375efe6038468e595bfd4e848940b9af6c6f563f00bbe26
affefaf1b5f42ab2d0e81c3f1b1fab9cdb8af95437cd4adf96e0b8030c762100
4003130247f2cab8b87f3d8de23293ddbc9568dbac75ad594abc7e01a04390d3
f69943bf5f5f8e9f52f7e14ac618334d5f17f30f7b8da8e702391f8127468bc2
c41f14cf5a0c8d407b70cf07f552a5ba26db3b23bfdbfae7b24e7ff8de7ec1a7
aa647fc681fd8d6d30e3c2cba0806841a997bfe5d93255ead639a42ae8a38648
dd52246f8570a4999ab97164e983621e794714fde1fa783d712a47c6117638d8
Domains
isns.net
api.db-ip.com
qxq.ddns.net
krupskaya.com
m-onetrading-jp.com
majul.com
thuocnam.tk
booking.msg.bluhotels.com
booking.msg.bluhotels.com
tr.bobcad.com
www.freedomshowers.com
www.ikea-club.org
nl.ikea-club.org
download.db-ip.com
api-netn.db-ip.com
www.beautypaths.eu
cdn.db-ip.com
api-osisoft.db-ip.com
api-mg2.db-ip.com
go.techtarget.com

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