Russian Cybercrime group is exploiting Zerologon flaw, Microsoft warns
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2020-1472 | Unauthenticated Privilege Escalation (Zerologon) in Microsoft Netlogon Domain Controllers CVE-2020-1472, widely known as "Zerologon," is an elevation-of-privilege flaw in how the Netlogon secure channel is established over the Netlogon Remote Protocol (MS-NRPC) on Microsoft domain controllers. An unauthenticated attacker with network reachability to a domain controller sends specially crafted Netlogon messages to establish a vulnerable secure channel and then runs a specially crafted application on the network to obtain domain administrator access. Successful exploitation yields domain administrator privileges, effectively full compromise of the Active Directory environment, and the flaw is known to be used in ransomware operations. Any organization running affected Windows Server versions (2008 through 20H2) as domain controllers is exposed, along with environments using Netlogon implementations from Samba and distributions or products from Fedora, openSUSE, Canonical (Ubuntu), Debian, Synology, and Oracle. Exploitation is highly active: a public Zerologon PoC/exploit is available, the flaw is on CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03, with known ransomware use), and EPSS estimates a 99.4% probability of exploitation within 30 days. Do: Apply the vendor updates on all domain controllers and other affected systems immediately, following Microsoft's two-phase Netlogon secure channel guidance (the enforcement phase of the phased rollout began in Q1 2021). Audit Netlogon secure-channel connections and event logs for clients still using vulnerable connections before enabling full enforcement, and install updated packages for Samba and other Netlogon implementations from Fedora, openSUSE, Ubuntu, Debian, Synology, and Oracle. Given known ransomware use, prioritize patching any domain controller reachable from user networks, VPNs, or the internet. | 5.5 | 99% | KEV ransomware PoC |
| massmillions of domain controllers worldwide (essentially every Active Directory domain), with hundreds of thousands of domain controllers/RPC endpoints… |
Full article549 words · extracted from securityaffairs.com · click to collapse
Microsoft has uncovered Zerologon attacks that were allegedly conducted by the infamous TA505 Russia-linked cybercrime group.
Microsoft spotted a series of Zerologon attacks allegedly launched by the Russian cybercrime group tracked as TA505, CHIMBORAZO and Evil Corp.
Microsoft experts spotted the Zerologon attacks involving fake software updates, the researchers noticed that the malicious code connected to command and control (C&C) infrastructure known to be associated with TA505.
TA505 hacking group has been active since 2014 focusing on Retail and banking sectors. The group is also known for some evasive techniques they put in place over time to avoid the security controls and penetrate corporate perimeters with several kinds of malware, for instance abusing the so-called LOLBins (Living Off The Land Binaries), legit programs regularly used by victim, or also the abuse of valid cryptographically signed payloads.
The TA505 group was involved in campaigns aimed at distributing the Dridex banking Trojan, along with Locky, BitPaymer, Philadelphia, GlobeImposter, and Jaff ransomware families.
Security experts from cyber-security firm Prevailion reported that TA505 has compromised more than 1,000 organizations.
The malicious updates employed in the Zerologon attacks are able to bypass the user account control (UAC) security feature in Windows and abuse the Windows Script Host tool (wscript.exe) to execute malicious scripts.
We’re seeing more activity leveraging the CVE-2020-1472 exploit (ZeroLogon). A new campaign shrewdly poses as software updates that connect to known CHIMBORAZO (TA505) C2 infrastructure. The fake updates lead to UAC bypass and use of wscript.exe to run malicious scripts.
— Microsoft Threat Intelligence (@MsftSecIntel) October 6, 2020
The experts explained that the threat actors abuse MSBuild.exe to compile Mimikatz updated with built-in ZeroLogon functionality.
To exploit the vulnerability, attackers abuse MSBuild.exe to compile Mimikatz updated with built-in ZeroLogon functionality.
— Microsoft Threat Intelligence (@MsftSecIntel) October 6, 2020
“Attacks showing up in commodity malware like those used by the threat actor CHIMBORAZO indicate broader exploitation in the near term.” states Microsoft.
This is the second alert published by Microsoft related to Zerologon attack in the wild. Early this week the IT giant published a post and a series of tweets warning of cyber attacks exploiting the Zerologon vulnerability carried out by the Iran-linked APT group known as MuddyWater, aka Mercury.
MSTIC has observed activity by the nation-state actor MERCURY using the CVE-2020-1472 exploit (ZeroLogon) in active campaigns over the last 2 weeks. We strongly recommend patching. Microsoft 365 Defender customers can also refer to these detections: https://t.co/ieBj2dox78
— Microsoft Threat Intelligence (@MsftSecIntel) October 5, 2020
The CVE-2020-1472 Zerologon flaw is an elevation of privilege that resides in the Netlogon. The Netlogon service is an Authentication Mechanism used in the Windows Client Authentication Architecture which verifies logon requests, and it registers, authenticates, and locates Domain Controllers.
An attacker could exploit the vulnerability to impersonate any computer, including the domain controller itself, and execute remote procedure calls on their behalf.
An attacker could also exploit the flaw to disable security features in the Netlogon authentication process and change a computer’s password on the domain controller’s Active Directory.
At the end of September, DHS CISA issued an emergency directive to tells government agencies to address the Zerologon vulnerability (CVE-2020-1472) by Monday.
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/109323/hacking/ta505-zerologon-attacks.html