Volt Typhoon

Data from Local System

Volt Typhoon has stolen files from a sensitive file server and the Active Directory database from targeted environments, and used Wevtutil to extract event log information.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Keylogging

Volt Typhoon has created and accessed a file named rult3uil.log on compromised domain controllers to capture keypresses and command execution.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Data Staged

Volt Typhoon has staged collected data in password-protected archives.(Citation: Microsoft Volt Typhoon May 2023)

Local Data Staging

Volt Typhoon has saved stolen files including the `ntds.dit` database and the `SYSTEM` and `SECURITY` Registry hives locally to the `C:\Windows\Temp\` directory.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)

Screen Capture

Volt Typhoon has obtained a screenshot of the victim's system using the gdi32.dll and gdiplus.dll libraries.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Archive via Utility

Volt Typhoon has archived the ntds.dit database as a multi-volume password-protected archive with 7-Zip.(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Proxy

Volt Typhoon has used compromised devices and customized versions of open source tools such as FRP (Fast Reverse Proxy), Earthworm, and Impacket to proxy network traffic.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Internal Proxy

Volt Typhoon has used the built-in netsh `port proxy` command to create proxies on compromised systems to facilitate access.(Citation: Microsoft Volt Typhoon May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Multi-hop Proxy

Volt Typhoon has used multi-hop proxies for command-and-control infrastructure.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Ingress Tool Transfer

Volt Typhoon has downloaded an outdated version of comsvcs.dll to a compromised domain controller in a non-standard folder.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Symmetric Cryptography

Volt Typhoon has used a version of the Awen web shell that employed AES encryption and decryption for C2 communications.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

LSASS Memory

Volt Typhoon has attempted to access hashed credentials from the LSASS process memory space.(Citation: Microsoft Volt Typhoon May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

NTDS

Volt Typhoon has used ntds.util to create domain controller installation media containing usernames and password hashes.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Unsecured Credentials

Volt Typhoon has obtained credentials insecurely stored on targeted network appliances.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Private Keys

Volt Typhoon has accessed a Local State file that contains the AES key used to encrypt passwords stored in the Chrome browser.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Credentials from Password Stores

Volt Typhoon has attempted to obtain credentials from OpenSSH, realvnc, and PuTTY.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)

Credentials from Web Browsers

Volt Typhoon has targeted network administrator browser data including browsing history and stored credentials.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Modify Registry

Volt Typhoon has used `netsh` to create a PortProxy Registry modification on a compromised server running the Paessler Router Traffic Grapher (PRTG).(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Clear Windows Event Logs

Volt Typhoon has selectively cleared Windows Event Logs, system logs, and other technical artifacts to remove evidence of intrusion activity.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Service Discovery

Volt Typhoon has used `net start` to list running services.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Application Window Discovery

Volt Typhoon has collected window title information from compromised systems.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Query Registry

Volt Typhoon has queried the Registry on compromised systems, `reg query hklm\software\`, for information on installed software including PuTTY.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Network Configuration Discovery

Volt Typhoon has executed multiple commands to enumerate network topology and settings including `ipconfig`, `netsh interface firewall show all`, and `netsh interface portproxy show all`.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)

Internet Connection Discovery

Volt Typhoon has employed Ping to check network connectivity.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Remote System Discovery

Volt Typhoon has used multiple methods, including Ping, to enumerate systems on compromised networks.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)

System Owner/User Discovery

Volt Typhoon has used public tools and executed the PowerShell command `Get-EventLog security -instanceid 4624` to identify associated user and computer account names.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Network Service Discovery

Volt Typhoon has used commercial tools, LOTL utilities, and appliances already present on the system for network service discovery.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Network Connections Discovery

Volt Typhoon has used `netstat -ano` on compromised hosts to enumerate network connections.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)

Process Discovery

Volt Typhoon has enumerated running processes on targeted systems including through the use of Tasklist.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Permission Groups Discovery

Volt Typhoon has used commercial tools, LOTL utilities, and appliances already present on the system for group and user discovery.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Local Groups

Volt Typhoon has run `net localgroup administrators` in compromised environments to enumerate accounts.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)

Domain Groups

Volt Typhoon has run `net group` in compromised environments to discover domain groups.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

File and Directory Discovery

Volt Typhoon has enumerated directories containing vulnerability testing and cyber related content and facilities data such as construction drawings.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Local Account

Volt Typhoon has executed `net user` and `quser` to enumerate local account information.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Domain Account

Volt Typhoon has run `net group /dom` and `net group "Domain Admins" /dom` in compromised environments for account discovery.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)

Peripheral Device Discovery

Volt Typhoon has obtained victim's screen dimension and display device information.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Time Discovery

Volt Typhoon has obtained the victim's system timezone.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Browser Information Discovery

Volt Typhoon has targeted the browsing history of network administrators.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Software Discovery

Volt Typhoon has queried the Registry on compromised systems for information on installed software.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Location Discovery

Volt Typhoon has obtained the victim's system current location.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Log Enumeration

Volt Typhoon has used `wevtutil.exe` and the PowerShell command `Get-EventLog security` to enumerate Windows logs to search for successful logons.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Local Storage Discovery

Volt Typhoon has discovered file system types, drive names, size, and free space on compromised systems.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Windows Management Instrumentation

Volt Typhoon has leveraged WMIC for execution, remote system discovery, and to create and use temporary directories.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

PowerShell

Volt Typhoon has used PowerShell including for remote system discovery.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Windows Command Shell

Volt Typhoon has used the Windows command line to perform hands-on-keyboard activities in targeted environments including for discovery.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Unix Shell

Volt Typhoon has used Brightmetricagent.exe which contains a command- line interface (CLI) library that can leverage command shells including Z Shell (zsh).(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Exploit Public-Facing Application

Volt Typhoon has gained initial access through exploitation of multiple vulnerabilities in internet-facing software and appliances such as Fortinet, Ivanti (formerly Pulse Secure), NETGEAR, Citrix, and Cisco.(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Remote Desktop Protocol

Volt Typhoon has moved laterally to the Domain Controller via RDP using a compromised account with domain administrator privileges.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Lateral Tool Transfer

Volt Typhoon has copied web shells between servers in targeted environments.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

External Remote Services

Volt Typhoon has used VPNs to connect to victim environments and enable post-exploitation actions.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Web Shell

Volt Typhoon has used webshells, including ones named AuditReport.jspx and iisstart.aspx, in compromised environments.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

Exploitation for Privilege Escalation

Volt Typhoon has gained initial access by exploiting privilege escalation vulnerabilities in the operating system or network services.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Gather Victim Identity Information

Volt Typhoon has gathered victim identify information during pre-compromise reconnaissance. (Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Email Addresses

Volt Typhoon has targeted the personal emails of key network and IT staff at victim organizations.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Gather Victim Network Information

Volt Typhoon has conducted extensive pre-compromise reconnaissance to learn about the target organization’s network.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Network Topology

Volt Typhoon has conducted extensive reconnaissance of victim networks including identifying network topologies.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Network Security Appliances

Volt Typhoon has identified target network security measures as part of pre-compromise reconnaissance.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Gather Victim Org Information

Volt Typhoon has conducted extensive reconnaissance pre-compromise to gain information about the targeted organization.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Identify Roles

Volt Typhoon has identified key network and IT staff members pre-compromise at targeted organizations.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Gather Victim Host Information

Volt Typhoon has conducted pre-compromise reconnaissance for victim host information.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Search Open Websites/Domains

Volt Typhoon has conducted pre-compromise web searches for victim information.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Search Victim-Owned Websites

Volt Typhoon has conducted pre-compromise reconnaissance on victim-owned sites.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Scan Databases

Volt Typhoon has used FOFA, Shodan, and Censys to search for exposed victim infrastructure.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Virtual Private Server

Volt Typhoon has compromised Virtual Private Servers (VPS) to proxy C2 traffic.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Server

Volt Typhoon has used compromised Paessler Router Traffic Grapher (PRTG) servers from other organizations for C2.(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Botnet

Volt Typhoon has used compromised Cisco and NETGEAR end-of-life SOHO routers implanted with KV Botnet malware to support operations.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Network Devices

Volt Typhoon has compromised small office and home office (SOHO) network edge devices, many of which were located in the same geographic area as the victim, to proxy network traffic.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)

Exploits

Volt Typhoon has exploited zero-day vulnerabilities for initial access.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Tool

Volt Typhoon has used legitimate network and forensic tools and customized versions of open-source tools for C2.(Citation: Microsoft Volt Typhoon May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Vulnerabilities

Volt Typhoon has used publicly available exploit code for initial access.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Direct Volume Access

Volt Typhoon has executed the Windows-native `vssadmin` command to create volume shadow copies.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Software Packing

Volt Typhoon has used the Ultimate Packer for Executables (UPX) to obfuscate the FRP client files BrightmetricAgent.exe and SMSvcService.ex) and the port scanning utility ScanLine.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Match Legitimate Resource Name or Location

Volt Typhoon has used legitimate looking filenames for compressed copies of the ntds.dit database and used names including cisco_up.exe, cl64.exe, vm3dservice.exe, watchdogd.exe, Win.exe, WmiPreSV.exe, and WmiPrvSE.exe for the Earthworm and Fast Reverse Proxy tools.(Citation: Joint Cybersecurity Advisory Volt Typhoon June 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Masquerade File Type

Volt Typhoon has appended copies of the ntds.dit database with a .gif file extension.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

File Deletion

Volt Typhoon has run `rd /S` to delete their working directories and deleted systeminfo.dat from `C:\Users\Public\Documentsfiles`.(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Clear Network Connection History and Configurations

Volt Typhoon has inspected server logs to remove their IPs.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

Valid Accounts

Volt Typhoon relies primarily on valid credentials for persistence.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Domain Accounts

Volt Typhoon has used compromised domain accounts to authenticate to devices on compromised networks.(Citation: Microsoft Volt Typhoon May 2023)(Citation: Secureworks BRONZE SILHOUETTE May 2023)(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

Deobfuscate/Decode Files or Information

Volt Typhoon has used Base64-encoded data to transfer payloads and commands, including deobfuscation via certutil.(Citation: Secureworks BRONZE SILHOUETTE May 2023)

System Binary Proxy Execution

Volt Typhoon has used native tools and processes including living off the land binaries or “LOLBins" to maintain and expand access to the victim networks.(Citation: CISA AA24-038A PRC Critical Infrastructure February 2024)

System Checks

Volt Typhoon has run system checks to determine if they were operating in a virtualized environment.(Citation: Microsoft Volt Typhoon May 2023)