Blog

No items found.

[Part 2] Top Cyber Hygiene Issues Leading to a Breach

Default blog imageDefault blog imageDefault blog imageDefault blog imageDefault blog imageDefault blog image
28
May 2019
28
May 2019
Spotting cyber hygiene issues caused by a lapse of attention requires AI tools that alert critical changes to network activity. Read part two here!

Read the first part: Part one — A perimeter in ruins

Earlier this month, I discussed some of the most critical challenges that today’s institutions face in their efforts to reinforce the network perimeter. Eliminating common attack vectors, from unauthorized uploads in the cloud to outdated protocol usage on-premise, is an essential step toward a more secure digital future.

Ultimately, however, I concluded that even flawless cyber hygiene at the perimeter will never be a panacea for all possible cyber-threats, since defenders cannot possibly address vulnerabilities about which they aren’t yet aware. Building strong borders is vital, clearly, but as attackers continue to launch novel attacks, even 50-foot walls are imperiled by 50-foot ladders.

Of course, such concerns become merely academic when your walls aren’t placed correctly, or watched attentively, or expanded when the digital estate grows. For countless employees and organizations alike, the allure of convenience has weakened the perimeter in all of these ways and more, rendering the work of cyber-criminals exponentially easier. Yet given the complexity of the modern enterprise, discovering exactly where users have cut corners is often difficult for human security teams alone. Spotting cyber hygiene issues caused by a lack of due diligence — like the five detailed below — therefore requires AI tools that alert on critical changes to network activity in real time.

Issue #6: Not keeping an inventory of hardware on the network

As all manner of non-traditional IT makes its way into workplaces around the world, keeping an inventory of these seamlessly integrated devices often proves an arduous undertaking, one that many organizations shirk altogether. Between app-controlled thermostats and smart refrigerators, connected cameras and Bluetooth sensors, few security teams possess a rigorous list of the hardware under their care.

Yet attaining 100% network visibility is a prerequisite to any viable security posture. Attackers are increasingly targeting poorly secured IoT devices to bypass the perimeter at its weakest points, before moving laterally to compromise more sensitive databases and machines. By analyzing all traffic from the entire enterprise, Darktrace detects when new devices come online and alert on any unusual activity from them with its AI models, some of which are:

  • Device / New Device with Attack Tools
  • Unusual Activity / Anomalous SMB Read & Write from New Device
  • Unusual Activity / Sustained Unusual Activity from New Device
  • Unusual Activity / Unusual Activity from New Device

Issue #7: Using corporate devices for private use

While the divide between corporate and private networks is a primary facet of cyber hygiene, few employees are immune to the temptation and convenience of using company devices for personal use. Whether it’s torrenting movies, visiting social media websites, or checking personal email accounts during the workday, these activities all expose carefully guarded corporate environments to ones that are far less secure. At the same time, many organizations lack visibility over their own online traffic, preventing their security teams from catching such risky behavior until it’s already too late.

Employees have also been known to violate internal compliance policies by downloading unauthorized software for private purposes, which introduces serious security risks and opens the door for supply chain attacks. Darktrace has detected a plethora of threats related to such downloads across our customer base, including outdated software, network scanners, BitTorrent clients, and crypto-mining programs. Such compliance issues trigger a number of Darktrace’s behavioral models, for example:

  • Anomalous File / EXE from Rare External Location
  • Anomalous File / Incoming RAR File
  • Compliance / BitTorrent
  • Compliance / Crypto Currency Mining Activity

To bypass compliance policies and access resources blocked by network administrators, employees often turn to VPNs as well as onion routing services like Tor, which facilitate anonymous communication. These services are equivalent to inhibiting security controls on the offending device; consequently, companies must have the ability to detect and terminate them whenever they are used on the network. Because Darktrace provides 100% visibility across the digital infrastructure, it can flag private VPN and Tor sessions with the following example models:

  • Anomalous Connection / New Outbound VPN
  • Compliance / Privacy VPN
  • Compliance / Tor Usage

Darktrace detected one such case earlier this year wherein a corporate device connected to a third-party VPN. Although this activity is not inherently risky or threatening in all situations, Darktrace’s understanding of the company’s network revealed that the device was the only one using the VPN — strongly suggesting a compliance violation. Moreover, when the device was not using the VPN service, it was seen making a large amount of HTTP post requests to another rare destination and displaying other signs of infection. It turned out that the device was infected with the elusive Ursnif trojan.

Figure 1: Darktrace’s external site summary showing that only one device in the network connected to the VPN.

Issue #8: Lack of strong access management

Ensuring that only rightful users have access to private company resources is a foundational component of cyber security. Yet as these users and their privileges continuously evolve, maintaining strong access management can be time-consuming and difficult.

Out of all the users in the network, the accounts to which the most attention should be paid are those with administrator or root privileges. While it is common to keep a tight control on high-privilege accounts, there are still organizations that find it hard to manage the access control well, making their devices more vulnerable to both malware and insider threats. In fact, even well-intentioned insiders can jeopardize the organization in the absence of strong access management, such as employees who download unauthorized software without understanding its associated risks.

Darktrace has a list of models to detect the unusual usage of credentials, including:

  • User / New Admin Credentials on Client
  • User / Overactive User Credential
  • SaaS / Unusual SaaS Administration

Issue #9: TFTP Usage

Trivial File Transfer Protocol (TFTP) is an application layer protocol commonly employed to transfer files between devices. Due to its relatively simplistic design and easy implementation, TFTP was very popular in the past. In the context of today’s sophisticated cyber-threats, however, TFTP has become highly insecure. Among the protocol’s numerous weaknesses from a cyber hygiene perspective is its lack of authentication mechanisms, a flaw which allows essentially anyone to read and write resources on the exposed device.

Darktrace’s Compliance / External TFTP model enables network administrators to detect any incoming TFTP connections from external IP addresses that don’t normally connect to the network. Crucially, Darktrace AI’s understanding what constitutes “normal” versus “abnormal” for each particular network serves to differentiate the most serious threats, as TFTP connections from a rare IP address are much more likely to be malicious than similar connections between known IP addresses on the network.

TFTP is just one example of insecure protocol usage – Darktrace monitors for the abnormal usage of various other attack-prone protocols as well. Another example is Telnet.

Issue #10: Unencrypted data transferred between internal and external devices

While encrypting communication can be a hassle, cleartext messages are liable to be intercepted or even altered by malicious actors — with potentially devastating ramifications. Indeed, Darktrace’s Compliance / FTP / Unusual Outbound FTP model has frequently flagged credentials being sent via unencrypted channels, which attackers could have used to access privileged resources within the company’s network.

In the first few months of 2019, Darktrace detected an unusual connection made to an external device on port 1414 using the IBM WebSphere MQ Protocol. When potentially sensitive information was transmitted in cleartext, Darktrace AI alerted the customer in real time.

Figure 2: Packet capture showing that potential sensitive information was captured

Sacrificing convenience for security in these most egregious cases remains the foundation of robust cyber hygiene, whether that means not torrenting Shrek 2 on a work laptop or taking inventory of the smart juicer in the office kitchen. Of course, just as no perimeter defenses are formidable enough to keep motivated attackers at bay, so too is there no level of due diligence sufficient to close off all possible attack vectors or ensure that all employees are compliant with internal policies. With cyber AI defenses like Darktrace, security teams have an extra set of eyes watching out for poor cyber hygiene practices across the entire digital infrastructure, empowering them to grow those infrastructures with confidence.

INSIDE THE SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
AUTHOR
ABOUT ThE AUTHOR
Max Heinemeyer
Chief Product Officer

Max is a cyber security expert with over a decade of experience in the field, specializing in a wide range of areas such as Penetration Testing, Red-Teaming, SIEM and SOC consulting and hunting Advanced Persistent Threat (APT) groups. At Darktrace, Max is closely involved with Darktrace’s strategic customers & prospects. He works with the R&D team at Darktrace, shaping research into new AI innovations and their various defensive and offensive applications. Max’s insights are regularly featured in international media outlets such as the BBC, Forbes and WIRED. Max holds an MSc from the University of Duisburg-Essen and a BSc from the Cooperative State University Stuttgart in International Business Information Systems.

Book a 1-1 meeting with one of our experts
share this article
USE CASES
No items found.
PRODUCT SPOTLIGHT
No items found.
COre coverage
No items found.

More in this series

No items found.

Blog

Email

How to Protect your Organization Against Microsoft Teams Phishing Attacks

Default blog imageDefault blog image
21
May 2024

The problem: Microsoft Teams phishing attacks are on the rise

Around 83% of Fortune 500 companies rely on Microsoft Office products and services1, with Microsoft Teams and Microsoft SharePoint in particular emerging as critical platforms to the business operations of the everyday workplace. Researchers across the threat landscape have begun to observe these legitimate services being leveraged more and more by malicious actors as an initial access method.

As Teams becomes a more prominent feature of the workplace many employees rely on it for daily internal and external communication, even surpassing email usage in some organizations. As Microsoft2 states, "Teams changes your relationship with email. When your whole group is working in Teams, it means you'll all get fewer emails. And you'll spend less time in your inbox, because you'll use Teams for more of your conversations."

However, Teams can be exploited to send targeted phishing messages to individuals either internally or externally, while appearing legitimate and safe. Users might receive an external message request from a Teams account claiming to be an IT support service or otherwise affiliated with the organization. Once a user has accepted, the threat actor can launch a social engineering campaign or deliver a malicious payload. As a primarily internal tool there is naturally less training and security awareness around Teams – due to the nature of the channel it is assumed to be a trusted source, meaning that social engineering is already one step ahead.

Screenshot of a Microsoft Teams message request from a Midnight Blizzard-controlled account (courtesy of Microsoft)
Figure 1: Screenshot of a Microsoft Teams message request from a Midnight Blizzard-controlled account (courtesy of Microsoft)

Microsoft Teams Phishing Examples

Microsoft has identified several major phishing attacks using Teams within the past year.

In July 2023, Microsoft announced that the threat actor known as Midnight Blizzard – identified by the United States as a Russian state-sponsored group – had launched a series of phishing campaigns via Teams with the aim of stealing user credentials. These attacks used previously compromised Microsoft 365 accounts and set up new domain names that impersonated legitimate IT support organizations. The threat actors then used social engineering tactics to trick targeted users into sharing their credentials via Teams, enabling them to access sensitive data.  

At a similar time, threat actor Storm-0324 was observed sending phishing lures via Teams containing links to malicious SharePoint-hosted files. The group targeted organizations that allow Teams users to interact and share files externally. Storm-0324’s goal is to gain initial access to hand over to other threat actors to pursue more dangerous follow-on attacks like ransomware.

For a more in depth look at how Darktrace stops Microsoft Teams phishing read our blog: Don’t Take the Bait: How Darktrace Keeps Microsoft Teams Phishing Attacks at Bay

The market: Existing Microsoft Teams security solutions are insufficient

Microsoft’s native Teams security focuses on payloads, namely links and attachments, as the principal malicious component of any phishing. These payloads are relatively straightforward to detect with their experience in anti-virus, sandboxing, and IOCs. However, this approach is unable to intervene before the stage at which payloads are delivered, before the user even gets the chance to accept or deny an external message request. At the same time, it risks missing more subtle threats that don’t include attachments or links – like early stage phishing, which is pure social engineering – or completely new payloads.

Equally, the market offering for Teams security is limited. Security solutions available on the market are always payload-focused, rather than taking into account the content and context in which a link or attachment is sent. Answering questions like:

  • Does it make sense for these two accounts to speak to each other?
  • Are there any linguistic indicators of inducement?

Furthermore, they do not correlate with email to track threats across multiple communication environments which could signal a wider campaign. Effectively, other market solutions aren’t adding extra value – they are protecting against the same types of threats that Microsoft is already covering by default.

The other aspect of Teams security that native and market solutions fail to address is the account itself. As well as focusing on Teams threats, it’s important to analyze messages to understand the normal mode of communication for a user, and spot when a user’s Teams activity might signal account takeover.

The solution: How Darktrace protects Microsoft Teams against sophisticated threats

With its biggest update to Darktrace/Email ever, Darktrace now offers support for Microsoft Teams. With that, we are bringing the same AI philosophy that protects your email and accounts to your messaging environment.  

Our Self-Learning AI looks at content and context for every communication, whether that’s sent in an email or Teams message. It looks at actual user behavior, including language patterns, relationship history of sender and recipient, tone and payloads, to understand if a message poses a threat. This approach allows Darktrace to detect threats such as social engineering and payloadless attacks using visibility and forensic capabilities that Microsoft security doesn’t currently offer, as well as early symptoms of account compromise.  

Unlike market solutions, Darktrace doesn’t offer a siloed approach to Teams security. Data and signals from Teams are shared across email to inform detection, and also with the wider Darktrace ActiveAI security platform. By correlating information from email and Teams with network and apps security, Darktrace is able to better identify suspicious Teams activity and vice versa.  

Interested in the other ways Darktrace/Email augments threat detection? Read our latest blog on how improving the quality of end-user reporting can decrease the burden on the SOC. To find our more about Darktrace's enduring partnership with Microsoft, click here.

References

[1] Essential Microsoft Office Statistics in 2024

[2] Microsoft blog, Microsoft Teams and email, living in harmony, 2024

Continue reading
About the author
Carlos Gray
Product Manager

Blog

Inside the SOC

Don’t Take the Bait: How Darktrace Keeps Microsoft Teams Phishing Attacks at Bay

Default blog imageDefault blog image
20
May 2024

Social Engineering in Phishing Attacks

Faced with increasingly cyber-aware endpoint users and vigilant security teams, more and more threat actors are forced to think psychologically about the individuals they are targeting with their phishing attacks. Social engineering methods like taking advantage of the human emotions of their would-be victims, pressuring them to open emails or follow links or face financial or legal repercussions, and impersonating known and trusted brands or services, have become common place in phishing campaigns in recent years.

Phishing with Microsoft Teams

The malicious use of the popular communications platform Microsoft Teams has become widely observed and discussed across the threat landscape, with many organizations adopting it as their primary means of business communication, and many threat actors using it as an attack vector. As Teams allows users to communicate with people outside of their organization by default [1], it becomes an easy entry point for potential attackers to use as a social engineering vector.

In early 2024, Darktrace/Apps™ identified two separate instances of malicious actors using Microsoft Teams to launch a phishing attack against Darktrace customers in the Europe, the Middle East and Africa (EMEA) region. Interestingly, in this case the attackers not only used a well-known legitimate service to carry out their phishing campaign, but they were also attempting to impersonate an international hotel chain.

Despite these attempts to evade endpoint users and traditional security measures, Darktrace’s anomaly detection enabled it to identify the suspicious phishing messages and bring them to the customer’s attention. Additionally, Darktrace’s autonomous response capability, was able to follow-up these detections with targeted actions to contain the suspicious activity in the first instance.

Darktrace Coverage of Microsoft Teams Phishing

Chats Sent by External User and Following Actions by Darktrace

On February 29, 2024, Darktrace detected the presence of a new external user on the Software-as-a-Service (SaaS) environment of an EMEA customer for the first time. The user, “REDACTED@InternationalHotelChain[.]onmicrosoft[.]com” was only observed on this date and no further activities were detected from this user after February 29.

Later the same day, the unusual external user created its first chat on Microsoft Teams named “New Employee Loyalty Program”. Over the course of around 5 minutes, the user sent 63 messages across 21 different chats to unique internal users on the customer’s SaaS platform. All these chats included the ‘foreign tenant user’ and one of the customer’s internal users, likely in an attempt to remain undetected. Foreign tenant user, in this case, refers to users without access to typical internal software and privileges, indicating the presence of an external user.

Darktrace’s detection of unusual messages being sent by a suspicious external user via Microsoft Teams.
Figure 1: Darktrace’s detection of unusual messages being sent by a suspicious external user via Microsoft Teams.
Advanced Search results showing the presence of a foreign tenant user on the customer’s SaaS environment.
Figure 2: Advanced Search results showing the presence of a foreign tenant user on the customer’s SaaS environment.

Darktrace identified that the external user had connected from an unusual IP address located in Poland, 195.242.125[.]186. Darktrace understood that this was unexpected behavior for this user who had only previously been observed connecting from the United Kingdom; it further recognized that no other users within the customer’s environment had connected from this external source, thereby deeming it suspicious. Further investigation by Darktrace’s analyst team revealed that the endpoint had been flagged as malicious by several open-source intelligence (OSINT) vendors.

External Summary highlighting the rarity of the rare external source from which the Teams messages were sent.
Figure 3: External Summary highlighting the rarity of the rare external source from which the Teams messages were sent.

Following Darktrace’s initial detection of these suspicious Microsoft Teams messages, Darktrace's autonomous response was able to further support the customer by providing suggested mitigative actions that could be applied to stop the external user from sending any additional phishing messages.

Unfortunately, at the time of this attack Darktrace's autonomous response capability was configured in human confirmation mode, meaning any autonomous response actions had to be manually actioned by the customer. Had it been enabled in autonomous response mode, it would have been able promptly disrupt the attack, disabling the external user to prevent them from continuing their phishing attempts and securing precious time for the customer’s security team to begin their own remediation procedures.

Darktrace autonomous response actions that were suggested following the ’Large Volume of Messages Sent from New External User’ detection model alert.
Figure 4: Darktrace autonomous response actions that were suggested following the ’Large Volume of Messages Sent from New External User’ detection model alert.

External URL Sent within Teams Chats

Within the 21 Teams chats created by the threat actor, Darktrace identified 21 different external URLs being sent, all of which included the domain "cloud-sharcpoint[.]com”. Many of these URLs had been recently established and had been flagged as malicious by OSINT providers [3]. This was likely an attempt to impersonate “cloud-sharepoint[.]com”, the legitimate domain of Microsoft SharePoint, with the threat actor attempting to ‘typo-squat’ the URL to convince endpoint users to trust the legitimacy of the link. Typo-squatted domains are commonly misspelled URLs registered by opportunistic attackers in the hope of gaining the trust of unsuspecting targets. They are often used for nefarious purposes like dropping malicious files on devices or harvesting credentials.

Upon clicking this malicious link, users were directed to a similarly typo-squatted domain, “InternatlonalHotelChain[.]sharcpoInte-docs[.]com”. This domain was likely made to appear like the SharePoint URL used by the international hotel chain being impersonated.

Redirected link to a fake SharePoint page attempting to impersonate an international hotel chain.
Figure 5: Redirected link to a fake SharePoint page attempting to impersonate an international hotel chain.

This fake SharePoint page used the branding of the international hotel chain and contained a document named “New Employee Loyalty Program”; the same name given to the phishing messages sent by the attacker on Microsoft Teams. Upon accessing this file, users would be directed to a credential harvester, masquerading as a Microsoft login page, and prompted to enter their credentials. If successful, this would allow the attacker to gain unauthorized access to a user’s SaaS account, thereby compromising the account and enabling further escalation in the customer’s environment.

Figure 6: A fake Microsoft login page that popped-up when attempting to open the ’New Employee Loyalty Program’ document.

This is a clear example of an attacker attempting to leverage social engineering tactics to gain the trust of their targets and convince them to inadvertently compromise their account. Many corporate organizations partner with other companies and well-known brands to offer their employees loyalty programs as part of their employment benefits and perks. As such, it would not necessarily be unexpected for employees to receive such an offer from an international hotel chain. By impersonating an international hotel chain, threat actors would increase the probability of convincing their targets to trust and click their malicious messages and links, and unintentionally compromising their accounts.

In spite of the attacker’s attempts to impersonate reputable brands, platforms, Darktrace/Apps was able to successfully recognize the malicious intent behind this phishing campaign and suggest steps to contain the attack. Darktrace recognized that the user in question had deviated from its ‘learned’ pattern of behavior by connecting to the customer’s SaaS environment from an unusual external location, before proceeding to send an unusually large volume of messages via Teams, indicating that the SaaS account had been compromised.

A Wider Campaign?

Around a month later, in March 2024, Darktrace observed a similar incident of a malicious actor impersonating the same international hotel chain in a phishing attacking using Microsoft Teams, suggesting that this was part of a wider phishing campaign. Like the previous example, this customer was also based in the EMEA region.  

The attack tactics identified in this instance were very similar to the previously example, with a new external user identified within the network proceeding to create a series of Teams messages named “New Employee Loyalty Program” containing a typo-squatted external links.

There were a few differences with this second incident, however, with the attacker using the domain “@InternationalHotelChainExpeditions[.]onmicrosoft[.]com” to send their malicious Teams messages and using differently typo-squatted URLs to imitate Microsoft SharePoint.

As both customers targeted by this phishing campaign were subscribed to Darktrace’s Proactive Threat Notification (PTN) service, this suspicious SaaS activity was promptly escalated to the Darktrace Security Operations Center (SOC) for immediate triage and investigation. Following their investigation, the SOC team sent an alert to the customers informing them of the compromise and advising urgent follow-up.

Conclusion

While there are clear similarities between these Microsoft Teams-based phishing attacks, the attackers here have seemingly sought ways to refine their tactics, techniques, and procedures (TTPs), leveraging new connection locations and creating new malicious URLs in an effort to outmaneuver human security teams and conventional security tools.

As cyber threats grow increasingly sophisticated and evasive, it is crucial for organizations to employ intelligent security solutions that can see through social engineering techniques and pinpoint suspicious activity early.

Darktrace’s Self-Learning AI understands customer environments and is able to recognize the subtle deviations in a device’s behavioral pattern, enabling it to effectively identify suspicious activity even when attackers adapt their strategies. In this instance, this allowed Darktrace to detect the phishing messages, and the malicious links contained within them, despite the seemingly trustworthy source and use of a reputable platform like Microsoft Teams.

Credit to Min Kim, Cyber Security Analyst, Raymond Norbert, Cyber Security Analyst and Ryan Traill, Threat Content Lead

Appendix

Darktrace Model Detections

SaaS Model

Large Volume of Messages Sent from New External User

SaaS / Unusual Activity / Large Volume of Messages Sent from New External User

Indicators of Compromise (IoCs)

IoC – Type - Description

https://cloud-sharcpoint[.]com/[a-zA-Z0-9]{15} - Example hostname - Malicious phishing redirection link

InternatlonalHotelChain[.]sharcpolnte-docs[.]com – Hostname – Redirected Link

195.242.125[.]186 - External Source IP Address – Malicious Endpoint

MITRE Tactics

Tactic – Technique

Phishing – Initial Access (T1566)

References

[1] https://learn.microsoft.com/en-us/microsoftteams/trusted-organizations-external-meetings-chat?tabs=organization-settings

[2] https://www.virustotal.com/gui/ip-address/195.242.125.186/detection

[3] https://www.virustotal.com/gui/domain/cloud-sharcpoint.com

Continue reading
About the author
Min Kim
Cyber Security Analyst
Our ai. Your data.

Elevate your cyber defenses with Darktrace AI

Start your free trial
Darktrace AI protecting a business from cyber threats.