Friday, June 21, 2024

Hive Ransomware Affiliate Attacking Microsoft Exchange Servers vulnerable to ProxyShell Flaw

The cybersecurity experts at Varonis security firm have recently discovered a Hive ransomware affiliate that has been deploying a variety of backdoors, including the Cobalt Strike beacon, in order to compromise the Microsoft Exchange servers that are vulnerable to the ProxyShell flaws.

By deploying these backdoors the threat actors perform the following tasks and activities:-

  • Network reconnaissance
  • Steal admin account credentials
  • Exfiltrate valuable data
  • Deploying file-encrypting payload

Here the experts at Varonis security firm have identified this flaw while investigating an attack on one of its users.

Hive Ransomware

Cybercriminals use the Hive ransomware to perform attacks against their victims in the form of extortion, and in June 2021 it was first observed.

The operators of Hive Ransomware primarily target the following sectors:-

  • Healthcare facilities
  • Nonprofits
  • Retailers
  • Energy providers
  • Other sectors worldwide

In order to enable affiliates to use Hive as desired, the system is designed and distributed as a ransomware-as-a-service.

Attack chain

From the initial compromise within 72 hours, the operators of Hive ransomware managed to encrypt the attacked environment and achieve its malicious goals.

In the Hive Ransmoware attack chain, there are a total of five stages, and here they are:-

  • Stage 1: ProxyShell and WebShell
  • Stage 2: Cobalt Strike
  • Stage 3: Mimikatz and Pass-The-Hash
  • Stage 4: Scanning for sensitive information
  • Stage 5: Ransomware deployment

There are three vulnerabilities in the Microsoft Exchange Server known as ProxyShell which enables the threat actors to perform RCE on affected installations of Microsoft Exchange Server without authentication under certain circumstances.

The three vulnerabilities are tracked as:- 

  • CVE-2021-34473
  • CVE-2021-34523
  • CVE-2021-31297

All the above-mentioned three security flaws are marked as critical with severity scores ranging from 7.2 (high) to 9.8. Hive affiliate’s recent exploit of ProxyShell shows that even after all these years there are still some vulnerable servers out there that can be targeted.

In an accessible Exchange directory, the threat actors plant four web shells and after that, they download the Cobalt Strike stagers by executing the PowerShell code.

After executing it they use Mimikatz to access more assets in the compromised network by stealing the password of a domain admin account.

Recommendations

There has been a significant increase in ransomware attacks over the last couple of years and this seems to be the preferred method of threat actors looking to maximize their ransom profits.

Here are the recommendations from the Varonis Forensics Team:-

  • Patch Exchange server to the latest Exchange Cumulative Update (CU).
  • Security Update (SU) provided by Microsoft.
  • Use complex passwords.
  • Always change passwords periodically.
  • To revoke local admin permissions from domain accounts always use the Microsoft LAPS solution.
  • Regularly check for and remove inactive or abandoned user accounts.
  • Block SMBv1 usage.
  • Always use SMB signing.
  • Restrict employee’s role.
  • Train employees in security principles.
  • Establish basic security practices.

You can follow us on LinkedinTwitterFacebook for daily Cybersecurity and hacking news updates.

Website

Latest articles

PrestaShop Website Under Injection Attack Via Facebook Module

A critical vulnerability has been discovered in the "Facebook" module (pkfacebook) from Promokit.eu for...

Beware Of Illegal OTT Platforms That Exposes Sensitive Personal Information

A recent rise in data breaches from illegal Chinese OTT platforms exposes that user...

Beware Of Zergeca Botnet with Advanced Scanning & Persistence Features

A new botnet named Zergeca has emerged, showcasing advanced capabilities that set it apart...

Mailcow Mail Server Vulnerability Let Attackers Execute Remote Code

Two critical vulnerabilities (CVE-2024-31204 and CVE-2024-30270) affecting Mailcow versions before 2024-04 allow attackers to...

Hackers Attacking Vaults, Buckets, And Secrets To Steal Data

Hackers target vaults, buckets, and secrets to access some of the most classified and...

Hackers Weaponizing Windows Shortcut Files for Phishing

LNK files, a shortcut file type in Windows OS, provide easy access to programs,...

New Highly Evasive SquidLoader Attacking Employees Mimic As Word Document

Researchers discovered a new malware loader named SquidLoader targeting Chinese organizations, which arrives as...
Guru baran
Guru baranhttps://gbhackers.com
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Free Webinar

API Vulnerability Scanning

71% of the internet traffic comes from APIs so APIs have become soft targets for hackers.Securing APIs is a simple workflow provided you find API specific vulnerabilities and protect them.In the upcoming webinar, join Vivek Gopalan, VP of Products at Indusface as he takes you through the fundamentals of API vulnerability scanning..
Key takeaways include:

  • Scan API endpoints for OWASP API Top 10 vulnerabilities
  • Perform API penetration testing for business logic vulnerabilities
  • Prioritize the most critical vulnerabilities with AcuRisQ
  • Workflow automation for this entire process

Related Articles