Windows Defender Exploit Guard: Reduce the attack surface against next-generation malware

Windows Defender Exploit Guard is a new set of intrusion prevention capabilities that ships with the Windows 10 Fall Creators Update. The four components of Windows Defender Exploit Guard are designed to lock down the device against a wide variety of attack vectors and block behaviors commonly us...

Exploit for CVE-2017-8759 detected and neutralized

The September 12, 2017 security updates from Microsoft include the patch for a previously unknown vulnerability exploited through Microsoft Word as an entry vector. Customers using Microsoft advanced threat solutions were already protected against this threat. The vulnerability, classified as...

Windows Defender ATP machine learning and AMSI: Unearthing script-based attacks that ‘live off the land’

Scripts are becoming the weapon of choice of sophisticated activity groups responsible for targeted attacks as well as malware authors who indiscriminately deploy commodity threats. Scripting engines such as JavaScript, VBScript, and PowerShell offer tremendous benefits to attackers. They run...

HAFNIUM targeting Exchange Servers with 0-day exploits

Update 03/08/2021: Microsoft continues to see multiple actors taking advantage of unpatched systems to attack organizations with on-premises Exchange Server. To aid defenders in investigating these attacks where Microsoft security products and tooling may not be deployed, we are releasing a feed ...

Zerologon is now detected by Microsoft Defender for Identity

There has been a huge focus on the recently patched CVE-2020-1472 Netlogon Elevation of Privilege vulnerability, widely known as ZeroLogon. While Microsoft strongly recommends that you deploy the latest security updates to your servers and devices, we also want to provide you with the best...

Windows Defender ATP machine learning and AMSI: Unearthing script-based attacks that ‘live off the land’

Scripts are becoming the weapon of choice of sophisticated activity groups responsible for targeted attacks as well as malware authors who indiscriminately deploy commodity threats. Scripting engines such as JavaScript, VBScript, and PowerShell offer tremendous benefits to attackers. They run...

Exploring the crypt: Analysis of the WannaCrypt ransomware SMB exploit propagation

Note: Read our latest comprehensive report on ransomware: Ransomware 1H 2017 review: Global outbreaks reinforce the value of security hygiene. On May 12, there was a major outbreak of WannaCrypt ransomware. WannaCrypt directly borrowed exploit code from the ETERNALBLUE exploit and the DoublePulsa...

When coin miners evolve, Part 2: Hunting down LemonDuck and LemonCat attacks

Note: In this two-part blog series, we expose a modern malware infrastructure and provide guidance for protecting against the wide range of threats it enables. Part 1 covered the evolution of the threat, how it spreads, and how it impacts organizations. Part 2 provides a deep dive on the attacker...

New ransomware, old techniques: Petya adds worm capabilities

Note: We have published a follow-up blog entry on this ransomware attack. We have new findings from our continued investigation, as well as platform mitigation and protection information: Windows 10 platform resilience against the Petya ransomware attack. Read our latest comprehensive report on...

Tech support scams persist with increasingly crafty techniques

Note: Our Tech support scams FAQ page has the latest info on this type of threat, including scammer tactics, fake error messages, and the latest scammer hotlines. You can also read our latest blog, New tech support scam launches communication or phone call app. Millions of users continue to...

Web shell attacks continue to rise

One year ago, we reported the steady increase in the use of web shells in attacks worldwide. The latest Microsoft 365 Defender data shows that this trend not only continued, it accelerated: every month from August 2020 to January 2021, we registered an average of 140,000 encounters of these threa...

Ransomware-as-a-service: Understanding the cybercrime gig economy and how to protect yourself

Microsoft processes 24 trillion signals every 24 hours, and we have blocked billions of attacks in the last year alone. Microsoft Security tracks more than 35 unique ransomware families and 250 unique threat actors across observed nation-state, ransomware, and criminal activities. That depth of...

Ransomware 1H 2017 review: Global outbreaks reinforce the value of security hygiene

In the first six months of 2017, ransomware threats reached new levels of sophistication. The same period also saw the reversal of a six-month downward trend in ransomware encounters. New ransomware code was released at a higher rate with increasing complexity. Two high-profile ransomware inciden...

Detecting stealthier cross-process injection techniques with Windows Defender ATP: Process hollowing and atom bombing

Advanced cyberattacks emphasize stealth and persistence: the longer they stay under the radar, the more they can move laterally, exfiltrate data, and cause damage. To avoid detection, attackers are increasingly turning to cross-process injection. Cross-process injection gives attackers the abilit...

Hardening Windows 10 with zero-day exploit mitigations

Cyberattacks involving zero-day exploits happen from time to time, affecting different platforms and applications. Over the years, Microsoft security teams have been working extremely hard to address these attacks. While delivering innovative solutions like Windows Defender Application Guard, whi...

Exploit kits remain a cybercrime staple against outdated software – 2016 threat landscape review series

Despite the disruption of Axpergle Angler, which dominated the landscape in early 2016, exploit kits as a whole continued to be a threat to PCs running unpatched software. Some of the most prominent threats, from malvertising to ransomware, used exploit kits to infect millions of computers...

Analyzing attacks using the Exchange vulnerabilities CVE-2022-41040 and CVE-2022-41082

October 1, 2022 update – Added information about Exploit:Script/ExchgProxyRequest.A, Microsoft Defender AV’s robust detection for exploit behavior related to this threat. We also removed a section on MFA as a mitigation, which was included in a prior version of this blog as standard guidance...

Analyzing attacks that exploit the CVE-2021-40444 MSHTML vulnerability

In August, Microsoft Threat Intelligence Center MSTIC identified a small number of attacks less than 10 that attempted to exploit a remote code execution vulnerability in MSHTML using specially crafted Microsoft Office documents. These attacks used the vulnerability, tracked as CVE-2021-40444, as...

Gartner names Microsoft a Leader in the 2021 Endpoint Protection Platforms Magic Quadrant

Our mission to empower defenders and protect and secure organizations has never been more important to us. Over the last year, our customers have faced unpredictable challenges and nearly overnight have had to quickly adapt in the face of a new hybrid work environment, evolving sophistication and...

Analyzing attacks taking advantage of the Exchange Server vulnerabilities

Microsoft continues to monitor and investigate attacks exploiting the recent on-premises Exchange Server vulnerabilities. These attacks are now performed by multiple threat actors ranging from financially motivated cybercriminals to state-sponsored groups. To help customers who are not able to...

Analysis of the Shadow Brokers release and mitigation with Windows 10 virtualization-based security

On April 14, a group calling themselves the Shadow Brokers caught the attention of the security community by releasing a set of weaponized exploits. Shortly thereafter, one of these exploits was used to create wormable malware that we now know as WannaCrypt, which targeted a large number of...

Twin zero-day attacks: PROMETHIUM and NEODYMIUM target individuals in Europe

Targeted attacks are typically carried out against individuals to obtain intellectual property and other valuable data from target organizations. These individuals are either directly in possession of the targeted information or are able to connect to networks where the information resides...

When coin miners evolve, Part 1: Exposing LemonDuck and LemonCat, modern mining malware infrastructure

Note: In this two-part blog series, we expose a modern malware infrastructure and provide guidance for protecting against the wide range of threats it enables. Part 1 covers the evolution of the threat, how it spreads, and how it impacts organizations. Part 2 is a deep dive on the attacker behavi...

WannaCrypt ransomware worm targets out-of-date systems

Note: Read our latest comprehensive report on ransomware: Ransomware 1H 2017 review: Global outbreaks reinforce the value of security hygiene. On May 12, 2017 we detected a new ransomware that spreads like a worm by leveraging vulnerabilities that have been previously fixed. While security update...

No slowdown in Cerber ransomware activity as 2016 draws to a close

Note: Read our latest comprehensive report on ransomware: Ransomware 1H 2017 review: Global outbreaks reinforce the value of security hygiene. As everybody else winds down for the holidays, the cybercriminals behind Cerber are busy ramping up their operations. Following our discovery of a spam...

The state of apps by Microsoft identity: Azure AD app gallery apps that made the most impact in 2020

2020 was an unprecedented year, to say the least. The COVID-19 global pandemic drastically changed how we work, learn, and collaborate. Organizations had to find new ways to connect and maintain productivity while providing secure access to critical apps and resources. Our own Microsoft services,...

Guidance for preventing, detecting, and hunting for exploitation of the Log4j 2 vulnerability

January 10, 2022 recap – The Log4j vulnerabilities represent a complex and high-risk situation for companies across the globe. This open-source component is widely used across many suppliers’ software and services. By nature of Log4j being a component, the vulnerabilities affect not only...

Threat actor DEV-0322 exploiting ZOHO ManageEngine ADSelfService Plus

Microsoft has detected exploits being used to compromise systems running the ZOHO ManageEngine ADSelfService Plus software versions vulnerable to CVE-2021-40539 in a targeted campaign. Microsoft Threat Intelligence Center MSTIC attributes this campaign with high confidence to DEV-0322, a group...

Exposing POLONIUM activity and infrastructure targeting Israeli organizations

Microsoft successfully detected and disabled attack activity abusing OneDrive by a previously undocumented Lebanon-based activity group Microsoft Threat Intelligence Center MSTIC tracks as POLONIUM. The associated indicators and tactics were used by the OneDrive team to improve detection of attac...

#AVGater vulnerability does not affect Windows Defender Antivirus, MSE, or SCEP

On November 10, 2017, a vulnerability called AVGater was discovered affecting some antivirus products. The vulnerability requires a non-administrator-level account to perform a restore of a quarantined file. Windows Defender Antivirus and other Microsoft antimalware products, including System...

Using Microsoft 365 Defender to protect against Solorigate

Microsoft security researchers continue to investigate and respond to the sophisticated cyberattack known as Solorigate also referred to as Sunburst by FireEye involving a supply chain compromise and the subsequent compromise of cloud assets. While the related investigations and impact assessment...

Deep dive into the Solorigate second-stage activation: From SUNBURST to TEARDROP and Raindrop

More than a month into the discovery of Solorigate, investigations continue to unearth new details that prove it is one of the most sophisticated and protracted intrusion attacks of the decade. Our continued analysis of threat data shows that the attackers behind Solorigate are skilled campaign...

Detecting and mitigating elevation-of-privilege exploit for CVE-2017-0005

On March 14, 2017, Microsoft released security bulletin MS17-013 to address CVE-2017-0005, a vulnerability in the Windows Win32k component that could potentially allow elevation of privileges. A report from a trusted partner identified a zero-day exploit for this vulnerability. The exploit target...

Guidance for investigating attacks using CVE-2023-23397

This guide provides steps organizations can take to assess whether users have been targeted or compromised by threat actors exploiting CVE-2023-23397. A successful exploit of this vulnerability can result in unauthorized access to an organization’s environment by triggering a Net-NTLMv2 hash leak...

GoldMax, GoldFinder, and Sibot: Analyzing NOBELIUM’s layered persistence

Microsoft continues to work with partners and customers to expand our knowledge of the threat actor behind the nation-state cyberattacks that compromised the supply chain of SolarWinds and impacted multiple other organizations. As we have shared previously, we have observed the threat actor using...

Evolving trends in Iranian threat actor activity – MSTIC presentation at CyberWarCon 2021

Over the past year, the Microsoft Threat Intelligence Center MSTIC has observed a gradual evolution of the tools, techniques, and procedures employed by malicious network operators based in Iran. At CyberWarCon 2021, MSTIC analysts presented their analysis of these trends in Iranian nation state...

Gamifying machine learning for stronger security and AI models

To stay ahead of adversaries, who show no restraint in adopting tools and techniques that can help them attain their goals, Microsoft continues to harness AI and machine learning to solve security challenges. One area we’ve been experimenting on is autonomous systems. In a simulated enterprise...

Automatic on-premises Exchange Server mitigation now in Microsoft Defender Antivirus

As cybercriminals continue to exploit unpatched on-premises versions of Exchange Server 2013, 2016, and 2019, we continue to actively work with customers and partners to help them secure their environments and respond to associated threats. To date, we have released a comprehensive Security Updat...

Microsoft finds new elevation of privilege Linux vulnerability, Nimbuspwn

Microsoft has discovered several vulnerabilities, collectively referred to as Nimbuspwn, that could allow an attacker to elevate privileges to root on many Linux desktop endpoints. The vulnerabilities can be chained together to gain root privileges on Linux systems, allowing attackers to deploy...

New sophisticated email-based attack from NOBELIUM

Microsoft Threat Intelligence Center MSTIC has uncovered a wide-scale malicious email campaign operated by NOBELIUM, the threat actor behind the attacks against SolarWinds, the SUNBURST backdoor, TEARDROP malware, GoldMax malware, and other related components. The campaign, initially observed and...

Preparing for your migration from on-premises SIEM to Azure Sentinel

The pandemic of 2020 has reshaped how we engage in work, education, healthcare, and more, accelerating the widespread adoption of cloud and remote-access solutions. In today’s workplace, the security perimeter extends to the home, airports, the gym—wherever you are. To keep pace, organizations...

Combing through the fuzz: Using fuzzy hashing and deep learning to counter malware detection evasion techniques

Today’s cybersecurity threats continue to find ways to fly and stay under the radar. Cybercriminals use polymorphic malware because a slight change in the binary code or script could allow the said threats to avoid detection by traditional antivirus software. Threat actors customize their wares...

Spotting brand impersonation with Swin transformers and Siamese neural networks

Every day, Microsoft Defender for Office 365 encounters millions of brand impersonation emails. Our security solutions use multiple detection and prevention techniques to help users avoid divulging sensitive information to phishers as attackers continue refining their impersonation tricks. In thi...

BazaCall: Phony call centers lead to exfiltration and ransomware

Our continued investigation into BazaCall campaigns, those that use fraudulent call centers that trick unsuspecting users into downloading the BazaLoader malware, shows that this threat is more dangerous than what’s been discussed publicly in other security blogs and covered by the media. Apart...

MERCURY leveraging Log4j 2 vulnerabilities in unpatched systems to target Israeli organizations

In recent weeks, the Microsoft Threat Intelligence Center MSTIC and Microsoft 365 Defender Research Team detected Iran-based threat actor MERCURY leveraging exploitation of Log4j 2 vulnerabilities in SysAid applications against organizations all located in Israel. MSTIC assesses with high...

Browser security beyond sandboxing

Security is now a strong differentiator in picking the right browser. We all use browsers for day-to-day activities like staying in touch with loved ones, but also for editing sensitive private and corporate documents, and even managing our financial assets. A single compromise through a web...

A playbook for modernizing security operations

The security community is continuously changing, growing, and learning from each other to better position the world against cyber threats. In the latest post from our new Voice of the Community blog series, Microsoft Product Marketing Manager Natalia Godyla talks with Dave Kennedy, Founder and...

Attackers use Morse code, other encryption methods in evasive phishing campaign

Cybercriminals attempt to change tactics as fast as security and protection technologies do. During our year-long investigation of a targeted, invoice-themed XLS.HTML phishing campaign, attackers changed obfuscation and encryption mechanisms every 37 days on average, demonstrating high motivation...

MERCURY and DEV-1084: Destructive attack on hybrid environment

April 2023 update – Microsoft Threat Intelligence has shifted to a new threat actor naming taxonomy aligned around the theme of weather. MERCURY is now tracked as Mango Sandstorm and DEV-1084 is now tracked as Storm-1084. To learn more about the new taxonomy represents the origin, unique traits,...

Privacy compliance for smart meter infrastructure with Microsoft Information Protection and Azure Purview

Smart meters and smart grid infrastructure have been deployed in many of the world’s electric distribution grids. They promise energy conservation, better grid management for utilities, electricity theft reduction, and a host of value-added services for consumers. To deliver on this promise, they...