Threat Recap: Darkside, Crysis, Negasteal, Coinminer

Insights and analysis by Miguel Ang, Raphael Centeno, Don Ovid Ladores, Nikko Tamaña, and Llallum Victoria

In the past few weeks, we have spotted notable developments for different types of threats. For ransomware, a new family named Darkside surfaced, while operators behind Crysis/Dharma released a hacking toolkit. For messaging threats, a targeted email campaign was used to propagate Negasteal/Agent Tesla. Finally, for fileless threats, a coinminer was seen bundled with legitimate applications.

Read on to know more about these findings.

Darkside ransomware surfaced

A new ransomware family named Darkside (detected by Trend Micro as Ransom.Win32.DARKSIDE.YXAH-THA) has emerged. Operators behind this ransomware threaten to publish unpaying victims’ data, a similar tactic employed by operators of ransomware families such as Maze and Nefilim. The file extension used to append the names of encrypted files is based on the victim’s MAC address.

According to the ransomware's Tor webpage, the threat actors behind the ransomware check the potential target company’s financial capability. From there, they determine how much ransom their targets will pay. It was also indicated that the operators will not attack organizations under the medical, education, non-profit, and government sectors.

Figure 1. A Darkside ransom note

Crysis operators released a hacking tool kit

Crysis/Dharma ransomware (detected by Trend Micro as Ransom.Win32.CRYSIS.TIBGGS) has released a hacking toolkit named Toolbox, Sophos reports. Toolbox contains Mimikatz to harvest passwords, NirSoft Remote Desktop PassView to steal remote desktop protocol (RDP) passwords, Hash Suite Tools Free to dump hashes, and other tools to help find target computers and deploy the ransomware payload. With this kit, even rookie hackers can infiltrate networks easily.

Crysis operates under a ransomware-as-a-service (RaaS) model, and this hacking tool only makes it easier for affiliates to spread the ransomware to more targets.

Negasteal/Agent Tesla delivered via emails targeting bank account holders

We recently found emails that deliver Negasteal/Agent Tesla (detected by Trend Micro as  TrojanSpy.MSIL.NEGASTEAL.DYSGXT) through malicious attachments. The scheme targets account holders of Krung Thai Bank. The email informs the recipient of a supposed “outward remittance transaction” worth almost US$9,000. This prompts users to download the attachment which contains a document that exploits CVE-2017-11882 (also known as Microsoft Office Memory Corruption Vulnerability), a 17-year old memory corruption issue in Microsoft Office, to download and run the malware payload.

Discovered in 2014, Negasteal has been known to send stolen information through web panel, FTP or SMTP. More recently, we spotted it being distributed through removable drives  as it harvests credentials from Becky! Internet Mail.

Figure 2. Sample email with malicious attachment containing Negasteal

Legitimate applications bundled with coinminer

We also found legitimate applications such as TeamViewer, Rufus, and YTD Video Downloader bundled with a fileless coinminer (detected by Trend Micro as Coinminer.Win32.MALXMR.THHADBO). These installers do not come from official download centers or app stores. Upon download, the legitimate application and a malicious script (VBS file) are dropped into the user’s system. The malicious script then connects to a site to download the coinminer loader, which will then be used to load the coinminer.

Bundling coinminers and other malware types with legitimate installers of applications (such as video conferencing apps) is not a novel strategy; however, users who are not yet too familiar with this fact might unwittingly download from suspicious sources and inadvertently compromise their systems. 

Figure 3. Coinminer bundled with TeamViewer installer


Figure 4. Obfuscated VBS file

Defense against a variety of threats

The fast-paced nature of the cybersecurity landscape means that threats emerge at every turn, creating a never-ending race between threat actors and security researchers. Enterprises and individual users should keep abreast of developments so that they can perform the necessary actions to prevent these threats from compromising their systems. As the popular adage says, “knowing is half the battle”.

To tackle a variety of threats, enterprises and users are advised to develop good security practices with the help of the following:

  • Only download apps from official download centers or app stores.
  • Never click links and download attachments from emails or any other messages that come from untrustworthy sources.
  • Regularly update software and applications to ensure that the latest vulnerabilities are patched.
  • Equip systems with security solutions that can block and defend against threats.

The following solutions can help secure against a variety of threats:

  • Trend Micro Apex One™ and Apex One Endpoint Sensor  – Employs behavioral analysis that protects against malicious scripts, injection, ransomware, and memory and browser attacks related to fileless threats.
  • Trend Micro XDR – Connects email, endpoints, servers, cloud workloads, and networks to detect and respond to threats earlier.
  •  Trend Micro™ Email Security – Uses enhanced machine learning and dynamic sandbox analysis for file and URL to stop email threats.

Overall, a multilayered security approach is advised to guard all possible threat entry points.

Indicators of compromise

Darkside ransomware

SHA-256 Trend Micro pattern detection
9cee5522a7ca2bfca7cd3d9daba23e9a30deb6205f56c12045839075f7627297
Ransom.Win32.DARKSIDE.YXAH-THA

URL

  • hxxp://darksidedxcftmqa[.]onion/

Crysis/Dharma ransomware

SHA-256 File name Trend Micro pattern detection
1cec5e4563e2c1570353e54a4ecc12ab4d896ab7227fd8651adcd56b884c0c1c GdAgentSrv.de.dll HackTool.Win64.CVE20160099.A
28042dd4a92a0033b8f1d419b9e989c5b8e32d1d2d881f5c8251d58ce35b9063 process-hacker-2-39.exe PUA.Win32.ProcHack.A
3680b9e492f49abc108313c62ceb0f009d5ed232c874cae8828c99ebf201e075 takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
47dc3672971c242154a36622145de7060f17f56af75d21e2130e4f57089f5e48 takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
75d9d85b152e030eb73d17c691203b49bf593ea6a4bddeae48ca255b22c2d36d takeaway_ps1 Trojan.PS1.CRYSIS.AA
77cbab006cf6a801dbd1c752659bddf28562fb8681d20305dd1dc0b1e105c67a takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
78983ad10fe05fadccb201dd3e8c7f952e93332433a42e3d331531c5497d1330 winhost.exe Ransom.Win32.CRYSIS.TIBGGQ
b0b8fd4f6ab383014ea225c2b7776735af059f526cd7c4fdbdcb2e99d074ade7 takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
b2d2f4ecbc680d590743044744b3ff33c38e4aeb0ada990b0ae7be8291368155 takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
b5a69f7c4a3681a753f3512e3b36ac06c6ddbb1129a3e87f8c722ff4f9834f0a purgeMemory.ps1 Trojan.PS1.KILLSVC.Ahacktool
edef024abe48d6ed7b4757d63a8fd448a8ecf1ad15afd39cc97c97b27ed4498e
takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
ef5f2ce1a4d68d656400906ae906b0c7e7f61017f14840a7ac145d59ee69a4bd takeaway.exe Ransom.Win32.CRYSIS.TIBGGS
f47e3555461472f23ab4766e4d5b6f6fd260e335a6abc31b860e569a720a5446 NS2.ex HackTool.Win32.NetTool.A

Negasteal/Agent Tesla

SHA-256 Trend Micro pattern detection
58e74875b3659fa34aa1ecefba1a43cc049b7bb1c83de5a26ec8045c60f1099e
Trojan.W97M.CVE201711882.YQUOOUM
6991150c06b278712b052377ef768ca80923ff9c3396e7de18fa0fbce7211c96 TrojanSpy.MSIL.NEGASTEAL.DYSGXT

Coinminer

SHA-256 Trend Micro pattern detection Trend Micro machine learning detection
12434186b803afd5e75b77bf8439d968ef0bb18ed8a871a279b95fe0a6c4e132
Coinminer.Win32.MALXMR.THHADBO
Troj.Win32.TRX.XXPE50FFF036
2da7be1ed9f13424c7b747caea0030b5b19007597640e9700add15bc8d236a1e Trojan.Win32.MALXMR.THHADBO Not Applicable
329788672911aaed64ba2add41a09f93b878bf8a3291c1309988acadb3643141 Trojan.VBS.MALXMR.THHADBO Not Applicable
663e4b7c209e864faaf598d791a9a6958c70f75bf974853d59bd15bc2a931163 Trojan.Win32.MALXMR.BX Not Applicable
9dade12201cc88cbd90f2fbaf4d50e512d4a377debad6714f19e10195e3a91be Trojan.Win32.MALXMR.BX Not Applicable
a24f84fa1302c9f4b68791532d2d7dbb0269e2ac2f245652164934289a1ba37e Trojan.Win32.MALXMR.BX Not Applicable
a78c0bd4cf9f4e21dea1fa67e92a6498c5df83c3ae57bb1f02d40da44e55cd69 Coinminer.Win32.MALXMR.THHADBO Troj.Win32.TRX.XXPE50FFF036
ae54783709a60e685846b3812d4e65b54672c8c40d2e8499fa92255ef89b7375 Trojan.Win32.MALXMR.BX Not Applicable
cd4b97c42b5ce9540f141498e2fdd4d566ea0b835d0c295994bf644744b5d4dd Trojan.Win32.MALXMR.BX Not Applicable

URLs

  • hxxps://pastebin[.]com/raw/jimA8sdx
  • hxxp://135[.]181[.]34[.]1/min3/loader23435345465446[.]jpg
  • hxxps://pastebin[.]com/raw/Yvyd9wXa
  • monerohash[.]com:3333
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