Virtual Event: Threat Detection and Incident Response Summit - Watch Sessions
Connect with us

Hi, what are you looking for?


Application Security

Microsoft Spots Multiple Nation-State APTs Exploiting Log4j Flaw

If defenders needed any more urgency to patch and mitigate the explosive Log4j zero-day, along comes word that APT actors linked to China, Iran, North Korea and Turkey have already pounced and are actively exploiting the CVSS 10.0 vulnerability.

If defenders needed any more urgency to patch and mitigate the explosive Log4j zero-day, along comes word that APT actors linked to China, Iran, North Korea and Turkey have already pounced and are actively exploiting the CVSS 10.0 vulnerability.

Security response teams at Microsoft on Wednesday confirmed nation-state hackers are poking at CVE-2021-44228 (the identifier for the Log4j vulnerability) to launch high-end malware implants.

Redmond’s Threat Intelligence Center (MSTIC) expressly identified nation-state backed hacking teams from China, Iran, North Korea, and Turkey as the adversaries exploiting the flaw.

“This activity ranges from experimentation during development, integration of the vulnerability to in-the-wild payload deployment, and exploitation against targets to achieve the actor’s objectives,” Microsoft said in a note on Log4j exploitation.

Microsoft’s findings confirm earlier reports from Mandiant that nation-state backed groups have added the Log4j exploit to malware toolkits.

[ READ: Exploits Swirling for Major Security Defect in Apache Log4j ]

Microsoft said the Iranian threat actor tracked as PHOSPHORUS (also known as Charming Kitten) has been seen acquiring and making modifications to the Log4j exploit for use in the wild. 

Advertisement. Scroll to continue reading.

“We assess that PHOSPHORUS has operationalized these modifications,” Microsoft warned, noting that the Iranian hacking group has been actively deploying ransomware for use in data extortion attacks.

Microsoft’s threat hunters said it also spotted HAFNIUM, a known threat actor group operating out of China, exploiting the Log4j vulnerability to attack virtualization infrastructure to extend typical APT targeting. 

“In these attacks, HAFNIUM-associated systems were observed using a DNS service typically associated with testing activity to fingerprint systems,” MIcrosoft warned.

The company did not share any specific information on observed hacking attacks from North Korea or Turkey.

[ SEE: Log4Shell Tools and Resources for Defenders – Continuously Updated ]

Microsoft also confirmed that multiple cybercrime groups that act as “access brokers” have started abusing the CVE-2021-44228 bug on both Windows and Linux systems to gain initial access to target networks. These access brokers then sell access to these networks to ransomware-as-a-service affiliates. 

Microsoft expects to see a surge in human-operated ransomware attacks on both Windows and Linux servers.

The software giant also observed signs of malicious botnet operators pouncing on the security defect to add compromised machines into computing pools to use for phishing and denial-of-service attacks.

“Microsoft has observed rapid uptake of this vulnerability into existing botnets like Mirai, existing campaigns previously targeting vulnerable Elasticsearch systems to deploy cryptocurrency miners, and activity deploying the Tsunami backdoor to Linux systems,” the company said.  

“Many of these campaigns are running concurrent scanning and exploitation activities for both Windows and Linux systems, using Base64 commands included in the JDNI:ldap:// request to launch bash commands on Linux and PowerShell on Windows,” the company added.

Related: Industrial Organizations Targeted in Log4Shell Attacks

Related: EXPLAINER: The Security Flaw That’s Freaked Out the Internet   

Related: Log4Shell Tools and Resources for Defenders (Continuously Updated)

Written By

Ryan Naraine is Editor-at-Large at SecurityWeek and host of the popular Security Conversations podcast series. He is a security community engagement expert who has built programs at major global brands, including Intel Corp., Bishop Fox and GReAT. Ryan is a founding-director of the Security Tinkerers non-profit, an advisor to early-stage entrepreneurs, and a regular speaker at security conferences around the world.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

SecurityWeek’s Threat Detection and Incident Response Summit brings together security practitioners from around the world to share war stories on breaches, APT attacks and threat intelligence.


Securityweek’s CISO Forum will address issues and challenges that are top of mind for today’s security leaders and what the future looks like as chief defenders of the enterprise.


Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

Data Protection

The cryptopocalypse is the point at which quantum computing becomes powerful enough to use Shor’s algorithm to crack PKI encryption.

Artificial Intelligence

The CRYSTALS-Kyber public-key encryption and key encapsulation mechanism recommended by NIST for post-quantum cryptography has been broken using AI combined with side channel attacks.


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.


A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Identity & Access

Zero trust is not a replacement for identity and access management (IAM), but is the extension of IAM principles from people to everyone and...