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Supply Chain Attack




Carderbee APT: After Hong Kong & Asia with PlugX Malware via Cobra DocGuard

Newly Discovered APT Group 'Carderbee' Strikes Hong Kong and Asia with PlugX Malware via Legitimate Cobra DocGuard Software, Suggesting Chinese State Links

4 min read

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US authorities warn of AvosLocker Ransomware cyberattacks targeting critical inf...

On October 11, 2023, the Cybersecurity and Infrastructure Security Agency (CISA) released a joint advisory on AvosLocker ransomware. AvosLocker is a Ransomware-as-a-Service group that employs double extortion tactics in ransomware attack campaigns. AvosLocker was first seen in June 2021, and they have multiple ransomware variants for Windows, Linux, and VMware ESXi environments. ## AvosLocker: A Ransomware-as-a-Service Powerhouse AvosLocker ransomware group emerged in June 2021. AvosLocker employs a Ransomware-as-a-Service (RaaS) business model and provides ransomware infrastructure to other threat actors for a percentage of the ransom payments. Like many other contemporary ransomware groups, AvosLocker also employs a double-extortion tactic. The group steals the victim's sensitive data and threatens to publish it on their "leak site" if the ransom isn't paid. This tactic puts additional pressure on victims, especially those who hold sensitive or confidential data. AvosLocker is known for attacking high-profile targets and demanding significant ransoms. In the recent past, they targeted critical infrastructure in different sectors in the US, Canada, the UK, and Spain. ## Initial Access: Compromised Credentials AvosLocker often uses common initial access techniques such as spear-phishing emails, exploiting vulnerable public-facing applications, or using compromised Remote Desktop Protocol (RDP) credentials. Using these valid accounts, adversaries gain initial access to the targets' networks via RDP or VPN. ### T1078 Valid Accounts AvosLocker ransomware operators acquire compromised credentials from Initial Access Brokers (IABs) and criminal forums/marketplaces. ### T1566 Phishing AvosLocker threat actors use spam email campaigns to deliver the ransomware payload to their targets. ### T1133 External Remote Services AvosLocker group uses remote system administration tools such as AnyDesk, PuTTy, Atera Agent, Splashtop Streamer, Tactical RMM, and PDQ Deploy to gain initial access to their targets. Zoho ManageEngine CVE-2021-40539 vulnerability is known to be exploited by AvosLocker threat actors as an initial access vector. ## Execution: Privilege Escalation and Lateral Movement After gaining initial access, adversaries upload custom webshells to establish persistence in the victim's network. Using known credential dumping tools, AvosLocker threat actors steal credentials from the compromised host and use them for lateral movement and privilege escalation. Prior to encryption, attackers exfiltrate the victim's sensitive files to an adversary-controlled command and control (C2) server. In the final step, AvosLocker reboots the infected machine in Safe Mode with Networking and encrypts the victim's sensitive files. ### T1059 Command and Scripting Interpreter Adversaries use custom batch files and PowerShell scripts for privilege escalation, lateral movement, and defense evasion. The names of the used scripts are Love.bat, lock.bat, update.bat, and AVO.ps1. #### Example 1: update.bat used by AvosLocker [2] ```batch @echo off sc config wuauserv start=disabled sc stop wuauserv ``` ### T1047 Windows Management Instrumentation AvosLocker uses legitimate Windows tools such as PsExec and nltest to interact with Windows Management Instrumentation and execute commands. ## Persistence: Establishing a Foothold After gaining initial access, AvosLocker operators upload custom webshells to establish persistence in the compromised network. ### T1505.003 Server Software Component: Web Shell ## Defense Evasion: Concealing the Attack Before deploying the ransomware payload, AvosLocker forces the infected Windows hosts into rebooting in Safe Mode. In Safe Mode, Windows does not enable many endpoint protections, and ransomware is less likely to be detected or prevented. ### T1562.009 Impair Defenses: Safe Mode Boot ## Credential Access: Stealing Passwords AvosLocker threat actors use known public credential dumping tools such as Mimikatz and LaZange to extract credentials from password storage mechanisms. ### T1555 Credentials from Password Stores ## Command and Control: Silent Communication AvosLocker uses open-source tools such as Ligolo and Chisel for secure communication between a compromised network and an adversary-controlled C2 server. By encrypting the channel and bypassing egress filtering, AvosLocker threat actors transfer malicious tools and steal sensitive data without being detected. ### T1572 Protocol Tunneling ## Impact: Encrypting Data AvosLocker ransomware uses a hybrid encryption methodology and combines AES-256-CBC and RSA to encrypt its victim's files. Depending on the version, encrypted files are appended with the .avos or .avos2 extension. ### T1486 Data Encrypted for Impact AvosLocker operators delete all volume shadow copies of the infected host to prevent victims from recovering their files. ```batch cmd /c wmic shadowcopy delete /nointeractive cmd /c vssadmin.exe Delete Shadows /All /Quiet ``` ## Mitigating AvosLocker Ransomware CISA previously released another cybersecurity advisory on AvosLocker ransomware in March 2022. Since then, the threat actors created new AvosLocker variants and added new capabilities to their arsenal. CISA recommends organizations continuously validate their security controls against the AvosLocker ransomware variants and their evolving threat behaviors. ### Secure Remote Access - Implement application controls to manage and control execution of software. - Apply recommendations in CISA's joint Guide to Securing Remote Access. - Frequently review and analyze log data. - Restrict access to resources over network connections. - Employ firewalls and intrusion detection/prevention systems to monitor and protect systems from Internet traffic. - Implement cybersecurity best practices and use strong passwords and two-factor authentication for all remote access. ### Security Posture - Establish network segmentation to restrict network traffic between the administrative network and the control network, as well as between the control network and the internet. - Limit network traffic with firewall rules. - Employ a least-privilege model. Restrict access to perform necessary system administration and maintenance. - Ensure systems have the latest security updates and are securely configured. ### Email Security - Implement a Sender Policy Framework (SPF) to identify servers that are authorized to send email on behalf of a domain. - Implement Domain-based Message Authentication, Reporting & Conformance (DMARC) to validate the authenticity of the email. - Utilize email security gateways. - Employ advanced anti-phishing technologies and monitor for phishing emails. ### User Training - Provide users with basic cybersecurity training. - Help users to be aware of the types of social engineering attacks and to be vigilant with email attachments. ## Conclusion The AvosLocker ransomware group has continued to evolve its tactics, techniques, and procedures since the previous advisory issued in March 2022. These threat actors target organizations in various sectors and have the potential to cause significant damage. It is essential for organizations to understand the group's techniques, adopt mitigation strategies, and continuously evaluate and enhance their security posture. This [Threat Research]( is based on information available on the public domain.

loading..   18-Oct-2023
loading..   1 min read




Explore Storm-0324 cyber threat tactics via Microsoft Teams phishing and stay pr...

Storm-0324, also known as DEV-0324, is a financially motivated threat group that has gained prominence for providing initial access to compromised networks. This group does not typically carry out the more damaging stages of intrusions, such as ransomware deployment, but instead specializes in gaining access and then selling that access to other malicious actors. Understanding and mitigating Storm-0324's activities is crucial because it can evade more destructive follow-on attacks. This [Threat Research]( analyzes the underlying aspects of this threat group and its involvement in Ransomware access broker stealing accounts via Microsoft Teams phishing. While this threat group has been on the radar for years, and their tactics have evolved over time, culminating in a recent shift towards using Microsoft Teams as a vector for phishing attacks. This research aims to dissect their techniques, tools, and procedures (TTPs) and provide insights into how to defend against them. ### Evolution of Storm-0324 Storm-0324 has a history dating back to at least 2016, when it was involved in distributing various malware payloads through different vectors. Over the years, they have employed a variety of first-stage payloads, including Nymaim, Gozi, [Trickbot](, Gootkit, Dridex, Sage ransomware, GandCrab ransomware, IcedID, and others. These payloads served as initial entry points into compromised networks. However, since 2019, Storm-0324 has primarily focused on distributing JSSLoader, a first-stage downloader that facilitates access for ransomware-as-a-service (RaaS) actors like Sangria Tempest, also known as ELBRUS, Carbon Spider, and FIN7. This tactic shift has been notable as it marks a collaboration with other cybercriminal groups. ### Email-Based Initial Infection Vectors Storm-0324 primarily relies on email-based infection vectors to distribute its payloads. Their email chains are designed to be highly evasive and make use of traffic distribution systems (TDS) like BlackTDS and Keitaro. These TDS systems help identify and filter user traffic, allowing the attackers to evade detection by security solutions, including malware sandboxes, while still successfully redirecting victims to malicious download sites. To lure victims into downloading malicious payloads, Storm-0324 typically employs themes related to invoices and payments, often mimicking popular services like DocuSign and Quickbooks. Once a user is enticed, they are redirected to a SharePoint-hosted compressed file containing JavaScript. The actors have used various file formats, including Microsoft Office documents, Windows Script Files (WSF), and VBScript, to execute the malicious code. ### Evolution to Microsoft Teams-Based Phishing One significant [development]( observed in Storm-0324's tactics according to Microsoft that an initial access broker known for working with ransomware groups has recently adopted to Microsoft Teams as a platform for phishing attacks to breach corporate networks. This shift was first noticed in July 2023, and it signifies an adaptation to the changing landscape of communication and collaboration tools. #### TeamsPhisher Tool To carry out these Teams-based phishing campaigns, Storm-0324 likely leverages a publicly available tool called [TeamsPhisher]( This Python-based tool enables users within a Teams tenant to attach files to messages sent to external tenants. While TeamsPhisher can be used legitimately, threat actors abuse it to deliver phishing attachments. This technique allows the actors to bypass certain restrictions related to incoming files from external sources. #### Phishing Lures in Teams Chats In these Teams-based phishing campaigns, Storm-0324 sends malicious links to potential victims over Microsoft Teams chats. These links lead to SharePoint-hosted files designed to deliver the malicious payload. The attackers take advantage of the fact that when external access is enabled within an organization's settings, these phishing lures appear as messages from "EXTERNAL" users. ### Attack Chain Overview To understand the attack chain employed by Storm-0324, let's break it down step by step: #### 1. Phishing Email Storm-0324 initiates its attack by sending phishing emails to potential victims. These emails typically reference invoices or payments and are carefully crafted to mimic legitimate services. #### 2. SharePoint-Hosted Archive The victim, enticed by the email, clicks on a link that leads to a SharePoint-hosted archive file. This archive usually contains a file with embedded JavaScript code. #### 3. Malicious JavaScript Upon opening the archive, the JavaScript code is executed. The actors have used various file formats for hosting the JavaScript, including WSF and Ekipa publisher files, often exploiting known vulnerabilities like [CVE-2023-21715]( for local security feature bypass. #### 4. JSSLoader Payload The JavaScript code drops a JSSLoader variant DLL onto the victim's system. JSSLoader is the first-stage downloader employed by Storm-0324. #### 5. Handoff to Sangria Tempest After successfully delivering the JSSLoader payload, Storm-0324 hands-off access to another cybercriminal group known as Sangria Tempest (also associated with FIN7). This collaboration enables the deployment of more damaging payloads, such as ransomware. #### 6. Additional Social Engineering In some cases, Storm-0324 employs protected documents with security codes or passwords in their initial communications to users. This tactic adds an extra layer of believability for users and is an anti-analysis measure. ### Recommendations for Defense Now that we have dissected Storm-0324's attack tactics, it is crucial to understand how to defend against this threat actor. Here are recommendations for hardening networks against Storm-0324 attacks: 1. **Phishing-Resistant Authentication**: Implement phishing-resistant authentication methods for users. 2. **Conditional Access**: Use Conditional Access authentication strength to require phishing-resistant authentication for employees and external users accessing critical applications. 3. **Domain Allowlisting**: Specify trusted Microsoft 365 organizations to define which external domains are allowed or blocked for chat and meetings. 4. **Auditing**: Keep Microsoft 365 auditing enabled to investigate audit records when required. 5. **Access Settings**: Understand and select the best access settings for external collaboration in your organization. 6. **Credential Hygiene**: Educate users about social engineering and credential phishing attacks, emphasizing the importance of not entering MFA codes sent via unsolicited messages. 7. **User Caution in Microsoft Teams**: Educate Microsoft Teams users to verify 'External' tagging on communication attempts from external entities, be cautious about sharing sensitive information, and never share account information or authorize sign-in requests over chat. 8. **Suspicious Link Scanning**: Configure Microsoft Defender for Office 365 to recheck links on click, providing URL scanning and verification to protect against malicious links. 9. **Least Privilege**: Practice the principle of least privilege and maintain credential hygiene, avoiding using domain-wide, administrator-level service accounts. 10. **Cloud-Delivered Protection**: Turn on cloud-delivered protection and automatic sample submission in Microsoft Defender Antivirus to identify and stop new and unknown threats. 11. **Attack Surface Reduction**: Enable attack surface reduction rules in Microsoft Defender to prevent standard attack techniques. ### Detection Details Microsoft provides several tools for detecting Storm-0324 activity: - **Microsoft 365 Defender**: Detects various threat components, including TrojanSpy:MSIL/JSSLoader, Trojan:Win32/Gootkit, Trojan:Win32/IcedId, Trojan:Win64/IcedId, and Trojan:Win32/Trickbot. - **Microsoft Defender Antivirus**: Identifies threat components as malware and provides protection against them. - **Microsoft Defender for Endpoint**: Generates alerts related to Storm-0324 activity in the security center. ### Hunting Queries For those using Microsoft 365 Defender, specific hunting queries can be employed to identify potential threats related to TeamsPhisher: ```markdown let allowedSharepointDomain = pack_array( 'mysharepointname' //customize Sharepoint domain name and add more domains as needed for your query ); // let executable = pack_array( 'exe', 'dll', 'xll', 'msi', 'application' ); let script = pack_array( 'ps1', 'py', 'vbs', 'bat' ); let compressed = pack_array( 'rar', '7z', 'zip', 'tar', 'gz' ); // let startTime = ago(1d); let endTime = now(); DeviceFileEvents | where Timestamp between (startTime..endTime) | where ActionType =~ 'FileCreated' | where InitiatingProcessFileName has 'teams.exe' or InitiatingProcessParentFileName has 'teams.exe' | where InitiatingProcessFileName !has 'update.exe' and InitiatingProcessParentFileName !has 'update.exe' | where FileOriginUrl has 'sharepoint' and FileOriginReferrerUrl has_any ('sharepoint', '') | extend fileExt = tolower(tostring(split(FileName,'.')[-1])) | where fileExt in (executable) or fileExt in (script) or fileExt in (compressed) | extend fileGroup = iff( fileExt in (executable),'executable','') | extend fileGroup = iff( fileExt in (script),'script',fileGroup) | extend fileGroup = iff( fileExt in (compressed),'compressed',fileGroup) // | extend sharePoint_domain = tostring(split(FileOriginUrl,'/')[2]) | where not (sharePoint_domain has_any (allowedSharepointDomain)) | project-reorder Timestamp, DeviceId, DeviceName, sharePoint_domain, FileName, FolderPath, SHA256, FileOriginUrl, FileOriginReferrerUrl ``` ### Microsoft Sentinel Microsoft Sentinel users can employ the TI Mapping analytics to match indicators mentioned in this research with data in their workspace. Additionally, Microsoft Sentinel offers detection and threat hunting content to detect post-exploitation activities related to Storm-0324.

loading..   18-Sep-2023
loading..   1 min read


Delve into ScarCruft's sophisticated cyber espionage: NPO Mashinostroyeniya brea...

In the ever-evolving landscape of cyber threats, understanding the intricacies of advanced persistent threat (APT) groups is crucial. ScarCruft, also known as APT37 or Reaper, is an espionage group active since at least 2012. This group's primary focus is South Korea, though it has also targeted other Asian countries. ScarCruft's interests primarily lie in government and military organizations, as well as companies linked to the interests of North Korea. This [Threat Research]( delves into the technical details of ScarCruft's sophisticated tools highlighting its capabilities, evolution, and operational context. ## ScarCruft's Strategic Targeting and Evolution ScarCruft, suspected to have state sponsorship, directs its efforts towards government entities and organizations linked to the Korean peninsula. This aligns with its pursuit of politically relevant information. There have been observations by security researchers of ScarCruft's evolution, characterized by the development of new exploits, an increased interest in mobile device data, and adept utilization of legitimate tools and services for cyber espionage. ## Path of Intrusion As with many APTs, ScarCruft's campaign initiation involves spear-phishing or exploiting compromised websites via 'watering-hole' tactics. These tactics serve as initial infection vectors, enabling the group to infiltrate selected victims. The first stage of infection showcases the group's sophistication in bypassing Windows User Account Control (UAC), permitting elevated privilege payload execution through code often used in legitimate penetration testing. ## Malware Concealment and Payload Execution To evade network-level detection, ScarCruft employs steganography, embedding malicious code within image files. This tactic obscures its intentions while infiltrating systems. The final stage of infection involves the deployment of a cloud service-based backdoor, ROKRAT. Operating stealthily, ROKRAT collects extensive data from victim devices and systems, forwarding it to cloud services like Box, Dropbox, pCloud, and Yandex.Disk. ## Mobile Device Data Theft and Bluetooth Fingerprinting Kaspersky Lab researchers discovered a growing interest within ScarCruft to steal data from mobile devices. Additionally, the group developed malware that utilizes the Windows Bluetooth API to fingerprint connected Bluetooth devices. This unique capability showcases ScarCruft's adaptability and pursuit of diverse avenues for information acquisition. ## Overlapping Patterns and Strategic Dynamics Intriguingly, ScarCruft and another group, DarkHotel, exhibit overlapping interests in terms of target profiles. Although their tools and techniques differ significantly, Kaspersky Lab has observed a shadowy coexistence between the two. ScarCruft's cautious and low-profile approach, coupled with its technical prowess, demonstrates its resourcefulness in tool development and deployment. ## Dolphin Backdoor: Unveiling Its Spying Capabilities** A previously unreported backdoor used by ScarCruft has been unveiled, dubbed Dolphin. This backdoor showcases a plethora of spying capabilities that underline the group's sophisticated approach to cyber espionage. Dolphin is strategically deployed on selected targets, where it systematically monitors drives and portable devices, exfiltrating files of interest, logs keystrokes, captures screenshots, and even steals browser credentials. This intricate set of functionalities is carefully orchestrated to serve ScarCruft's covert objectives. ![Dolphin_Figure_1.png]( ***Overview of the Dolphin backdoor*** ## Deployment & Functionality Dolphin serves as the final payload of a multistage attack, often following an initial compromise using less advanced malware. One instance involved a watering-hole attack on a South Korean online newspaper, coupled with an Internet Explorer exploit and another ScarCruft backdoor named BLUELIGHT. This orchestration exemplifies ScarCruft's multifaceted approach to breaching its targets. The backdoor's evolution is evident through its various versions, each exhibiting improvements and adaptations to evade detection. For instance, earlier versions of Dolphin modified victims' signed-in Google and Gmail account settings to lower their security, potentially ensuring prolonged access to compromised email inboxes. ![Dolphin_Figure_3(1).png]( ***Backdoor Configuration*** ## Technical Analysis of Dolphin Backdoor The Dolphin backdoor's technical intricacies are worth exploring, offering insights into ScarCruft's advanced techniques. Dolphin's deployment involves an installer that downloads a Python interpreter and generates a loading chain with its payload. Persistence is achieved by creating a Run registry value, ensuring the loading chain's execution upon system startup. The Dolphin loader is a multi-step process involving a Python script and shellcode. The script decrypts and executes shellcode, which further creates a host process, decrypts additional shellcode, and injects it into the process. This multi-layered approach demonstrates ScarCruft's dedication to maintaining control over the compromised system. ## Capabilities & Advanced Techniques Dolphin's capabilities extend beyond traditional backdoor functionalities. Its ability to exfiltrate files extends to both fixed drives and portable devices, including smartphones. The backdoor's support for shellcode execution, shell command execution, and even keylogging underscores its comprehensive toolkit for information gathering. An intriguing feature is Dolphin's interaction with Google accounts. The backdoor manipulates Google account settings, lowering their security, and enabling access to Gmail via IMAP. This complex maneuvering is indicative of ScarCruft's determination to maintain access to victims' emails and sensitive data. ## Evolution & Evasion Tactics The evolution of the Dolphin backdoor showcases ScarCruft's commitment to innovation. Versions 2.0 and 3.0 introduced significant changes, including dynamic resolution of suspicious APIs, improvements in shellcode capabilities, and enhancements in device and drive detection for file exfiltration. Notably, the restoration of the credential-stealing command in version 3.0, albeit in a different form, demonstrates the group's adaptability. ![Dolphin_Figure_4.png]( ***Evolution Timeline*** ## Technical Analysis: ScarCruft's Intrusion and 'OpenCarrot' Backdoor In this section, we delve deep into the technical aspects of ScarCruft's cyberattack on NPO Mashinostroyeniya. We examine the attack vector, the deployment of the 'OpenCarrot' backdoor, its capabilities, and the potential collaboration with the Lazarus Group. Additionally, we analyze the associated code bases, code blocks, and scripts that provide insights into the group's sophisticated tactics. ## Attack Vector & Initial Compromise ScarCruft's intrusion likely began with a meticulously crafted spear-phishing campaign targeting NPO Mashinostroyeniya's employees. The group's knowledge of the company's activities and interests may have facilitated the creation of convincing phishing lures. Once an employee was deceived into interacting with a malicious attachment or link, the attackers gained a foothold within the network. ## Deploying the 'OpenCarrot' Backdoor Central to this attack was deploying the 'OpenCarrot' backdoor, a DLL-based implant known for its association with ScarCruft and the Lazarus Group. The backdoor's multifaceted capabilities make it a potent tool for maintaining persistent access and executing various commands within the compromised environment. ### Detailed Analysis of 'OpenCarrot' Functionality The 'OpenCarrot' backdoor boasts an array of functionalities, each contributing to its overall effectiveness: - **Reconnaissance:** ScarCruft leverages the backdoor's reconnaissance capabilities to identify valuable targets within the network. The malware enumerates file and process attributes, scans internal systems, and pings host for open ports, providing the attackers with a comprehensive view of the network landscape. - **Filesystem and Process Manipulation:** The backdoor empowers ScarCruft to manipulate files and processes on compromised systems. This includes the ability to terminate processes, inject malicious DLLs, delete or rename files, and manipulate timestamps to evade detection. - **Adaptive C2 Communication:** 'OpenCarrot' excels in maintaining command and control communications while evading detection. The backdoor can dynamically reconfigure its C2 infrastructure, terminating existing channels and establishing new ones as needed. This adaptability allows ScarCruft to stay ahead of defensive measures. ## Incorporating Sleeper Functionality and Lateral Movement A notable feature of the 'OpenCarrot' backdoor is its "sleeper function." This functionality enables the malware to enter a sleep state when legitimate users interact with compromised devices, reducing the risk of detection. Moreover, the malware continuously monitors for the insertion of new USB drives, potentially for lateral movement or data exfiltration. ![email.jpg]( ***New Drive Connection*** ## Collaboration with Lazarus Group: A Shared Toolset The presence of 'OpenCarrot' raises intriguing questions about collaboration or knowledge sharing between ScarCruft and the Lazarus Group. The use of this backdoor by both groups suggests a possible intersection of tactics and toolsets. While their motivations and targets may differ, the shared utilization of 'OpenCarrot' underscores the evolving dynamics of state-sponsored cyber threats. ## Code Analysis & Insights Detailed analysis of the code, scripts, and associated artifacts linked to the 'OpenCarrot' backdoor provides insights into the intricacies of ScarCruft's operations. These artifacts offer cybersecurity professionals a chance to dissect the group's techniques, learn from their tactics, and enhance defense mechanisms.

loading..   17-Aug-2023
loading..   1 min read