Techniques

Adversaries may attempt to get a listing of services running on remote hosts and local network infrastructure devices, including those that may be vulnerable to remote software exploitation. Common methods to acquire this information include port, vulnerability, and/or wordlist scans using tools that are brought onto a system.[1]

Within cloud environments, adversaries may attempt to discover services running on other cloud hosts. Additionally, if the cloud environment is connected to a on-premises environment, adversaries may be able to identify services running on non-cloud systems as well.

Within macOS environments, adversaries may use the native Bonjour application to discover services running on other macOS hosts within a network. The Bonjour mDNSResponder daemon automatically registers and advertises a host’s registered services on the network. For example, adversaries can use a mDNS query (such as dns-sd -B _ssh._tcp .) to find other systems broadcasting the ssh service.[2][3]

Adversaries may attempt to get a listing of services running on remote hosts, including those that may be vulnerable to remote software exploitation. Methods to acquire this information include port scans and vulnerability scans from the mobile device. This technique may take advantage of the mobile device's access to an internal enterprise network either through local connectivity or through a Virtual Private Network (VPN).

Network Service Scanning is the process of discovering services on networked systems. This can be achieved through a technique called port scanning or probing. Port scanning interacts with the TCP/IP ports on a target system to determine whether ports are open, closed, or filtered by a firewall. This does not reveal the service that is running behind the port, but since many common services are run on [https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml specific port numbers], the type of service can be assumed. More in-depth testing includes interaction with the actual service to determine the service type and specific version. One of the most-popular tools to use for Network Service Scanning is [https://nmap.org/ Nmap].

An adversary may attempt to gain information about a target device and its role on the network via Network Service Scanning techniques, such as port scanning. Network Service Scanning is useful for determining potential vulnerabilities in services on target devices. Network Service Scanning is closely tied to .

Scanning ports can be noisy on a network. In some attacks, adversaries probe for specific ports using custom tools. This was specifically seen in the Triton and PLC-Blaster attacks.

Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation. Windows shared drive and SMB/Windows Admin Shares connections can be removed when no longer needed. Net is an example utility that can be used to remove network share connections with the net use \\system\share /delete command. [1]

Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation. Windows shared drive and Windows Admin Shares connections can be removed when no longer needed. Net is an example utility that can be used to remove network share connections with the net use \\system\share /delete command. [1]

Adversaries may look for folders and drives shared on remote systems as a means of identifying sources of information to gather as a precursor for Collection and to identify potential systems of interest for Lateral Movement. Networks often contain shared network drives and folders that enable users to access file directories on various systems across a network.

File sharing over a Windows network occurs over the SMB protocol. [1] [2] Net can be used to query a remote system for available shared drives using the net view \\\\remotesystem command. It can also be used to query shared drives on the local system using net share. For macOS, the sharing -l command lists all shared points used for smb services.

Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network. Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.

Data captured via this technique may include user credentials, especially those sent over an insecure, unencrypted protocol. Techniques for name service resolution poisoning, such as Name Resolution Poisoning and SMB Relay, can also be used to capture credentials to websites, proxies, and internal systems by redirecting traffic to an adversary.

Network sniffing may reveal configuration details, such as running services, version numbers, and other network characteristics (e.g. IP addresses, hostnames, VLAN IDs) necessary for subsequent Lateral Movement and/or Stealth activities. Adversaries may likely also utilize network sniffing during Adversary-in-the-Middle (AiTM) to passively gain additional knowledge about the environment.

In cloud-based environments, adversaries may still be able to use traffic mirroring services to sniff network traffic from virtual machines. For example, AWS Traffic Mirroring, GCP Packet Mirroring, and Azure vTap allow users to define specified instances to collect traffic from and specified targets to send collected traffic to.[1][2][3] Often, much of this traffic will be in cleartext due to the use of TLS termination at the load balancer level to reduce the strain of encrypting and decrypting traffic.[4][5] The adversary can then use exfiltration techniques such as Transfer Data to Cloud Account in order to access the sniffed traffic.[4]

On network devices, adversaries may perform network captures using Network Device CLI commands such as `monitor capture`.[6][7]

Network sniffing is the practice of using a network interface on a computer system to monitor or capture information [1] regardless of whether it is the specified destination for the information.

An adversary may attempt to sniff the traffic to gain information about the target. This information can vary in the level of importance. Relatively unimportant information is general communications to and from machines. Relatively important information would be login information. User credentials may be sent over an unencrypted protocol, such as Telnet, that can be captured and obtained through network packet analysis.

In addition, ARP and Domain Name Service (DNS) poisoning can be used to capture credentials to websites, proxies, and internal systems by redirecting traffic to an adversary.

Adversaries may gather information about the victim's network topology that can be used during targeting. Information about network topologies may include a variety of details, including the physical and/or logical arrangement of both external-facing and internal network environments. This information may also include specifics regarding network devices (gateways, routers, etc.) and other infrastructure.

Adversaries may gather this information in various ways, such as direct collection actions via Active Scanning or Phishing for Information. Information about network topologies may also be exposed to adversaries via online or other accessible data sets (ex: Search Victim-Owned Websites).[1] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Technical Databases or Search Open Websites/Domains), establishing operational resources (ex: Acquire Infrastructure or Compromise Infrastructure), and/or initial access (ex: External Remote Services).

An adversary may capture network traffic to and from the device to obtain credentials or other sensitive data, or redirect network traffic to flow through an adversary-controlled gateway to do the same.

A malicious app could register itself as a VPN client on Android or iOS to gain access to network packets. However, on both platforms, the user must grant consent to the app to act as a VPN client, and on iOS the app requires a special entitlement that must be granted by Apple.

Alternatively, if a malicious app is able to escalate operating system privileges, it may be able to use those privileges to gain access to network traffic.

An adversary could redirect network traffic to an adversary-controlled gateway by establishing a VPN connection or by manipulating the device's proxy settings. For example, Skycure [1] describes the ability to redirect network traffic by installing a malicious iOS Configuration Profile.

If applications encrypt their network traffic, sensitive data may not be accessible to an adversary, depending on the point of capture.

Adversaries may gather information about the victim's network trust dependencies that can be used during targeting. Information about network trusts may include a variety of details, including second or third-party organizations/domains (ex: managed service providers, contractors, etc.) that have connected (and potentially elevated) network access.

Adversaries may gather this information in various ways, such as direct elicitation via Phishing for Information. Information about network trusts may also be exposed to adversaries via online or other accessible data sets (ex: Search Open Technical Databases).[1] Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Active Scanning or Search Open Websites/Domains), establishing operational resources (ex: Acquire Infrastructure or Compromise Infrastructure), and/or initial access (ex: Trusted Relationship).

When operating systems boot up, they can start programs or applications called services that perform background system functions. [1] A service's configuration information, including the file path to the service's executable, is stored in the Windows Registry.

Adversaries may install a new service that can be configured to execute at startup by using utilities to interact with services or by directly modifying the Registry. The service name may be disguised by using a name from a related operating system or benign software with Masquerading. Services may be created with administrator privileges but are executed under SYSTEM privileges, so an adversary may also use a service to escalate privileges from administrator to SYSTEM. Adversaries may also directly start services through Service Execution.

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive.[1] Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).

ICMP communication between hosts is one example.[2] Because ICMP is part of the Internet Protocol Suite, it is required to be implemented by all IP-compatible hosts.[3] However, it is not as commonly monitored as other Internet Protocols such as TCP or UDP and may be used by adversaries to hide communications.

In ESXi environments, adversaries may leverage the Virtual Machine Communication Interface (VMCI) for communication between guest virtual machines and the ESXi host. This traffic is similar to client-server communications on traditional network sockets but is localized to the physical machine running the ESXi host, meaning it does not traverse external networks (routers, switches). This results in communications that are invisible to external monitoring and standard networking tools like tcpdump, netstat, nmap, and Wireshark. By adding a VMCI backdoor to a compromised ESXi host, adversaries may persistently regain access from any guest VM to the compromised ESXi host’s backdoor, regardless of network segmentation or firewall rules in place.[4]

Adversaries may encode data with a non-standard data encoding system to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a non-standard data encoding system that diverges from existing protocol specifications. Non-standard data encoding schemes may be based on or related to standard data encoding schemes, such as a modified Base64 encoding for the message body of an HTTP request.[1][2]

Adversaries may communicate using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088[1] or port 587[2] as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data.

Adversaries may also make changes to victim systems to abuse non-standard ports. For example, Registry keys and other configuration settings can be used to modify protocol and port pairings.[3]

Adversaries may generate network traffic using a protocol and port pairing that are typically not associated. For example, HTTPS over port 8088 or port 587 as opposed to the traditional port 443. Adversaries may make changes to the standard port used by a protocol to bypass filtering or muddle analysis/parsing of network data.

Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password. Credentials can be obtained from OS caches, memory, or structures.[1] Credentials can then be used to perform Lateral Movement and access restricted information.

Several of the tools mentioned in associated sub-techniques may be used by both adversaries and professional security testers. Additional custom tools likely exist as well.

Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS). A system's OS is responsible for managing the finite resources as well as preventing the entire system from being overwhelmed by excessive demands on its capacity. These attacks do not need to exhaust the actual resources on a system; the attacks may simply exhaust the limits and available resources that an OS self-imposes.

Different ways to achieve this exist, including TCP state-exhaustion attacks such as SYN floods and ACK floods.[1] With SYN floods, excessive amounts of SYN packets are sent, but the 3-way TCP handshake is never completed. Because each OS has a maximum number of concurrent TCP connections that it will allow, this can quickly exhaust the ability of the system to receive new requests for TCP connections, thus preventing access to any TCP service provided by the server.[2]

ACK floods leverage the stateful nature of the TCP protocol. A flood of ACK packets are sent to the target. This forces the OS to search its state table for a related TCP connection that has already been established. Because the ACK packets are for connections that do not exist, the OS will have to search the entire state table to confirm that no match exists. When it is necessary to do this for a large flood of packets, the computational requirements can cause the server to become sluggish and/or unresponsive, due to the work it must do to eliminate the rogue ACK packets. This greatly reduces the resources available for providing the targeted service.[3]

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open and Deobfuscate/Decode Files or Information for User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.[1] Adversaries may also use compressed or archived scripts, such as JavaScript.

Portions of files can also be encoded to hide the plain-text strings that would otherwise help defenders with discovery.[2] Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.[3]

Adversaries may also abuse Command Obfuscation to obscure commands executed from payloads or directly via Command and Scripting Interpreter. Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and application control mechanisms.[4][5][6]

Adversaries may attempt to make a payload or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the device or in transit. This is common behavior that can be used across different platforms and the network to evade defenses. Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Portions of files can also be encoded to hide the plaintext strings that would otherwise help defenders with discovery. Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.[1]

Adversaries may buy and/or steal capabilities that can be used during targeting. Rather than developing their own capabilities in-house, adversaries may purchase, freely download, or steal them. Activities may include the acquisition of malware, software (including licenses), exploits, certificates, and information relating to vulnerabilities. Adversaries may obtain capabilities to support their operations throughout numerous phases of the adversary lifecycle.

In addition to downloading free malware, software, and exploits from the internet, adversaries may purchase these capabilities from third-party entities. Third-party entities can include technology companies that specialize in malware and exploits, criminal marketplaces, or from individuals.[1][2]

In addition to purchasing capabilities, adversaries may steal capabilities from third-party entities (including other adversaries). This can include stealing software licenses, malware, SSL/TLS and code-signing certificates, or raiding closed databases of vulnerabilities or exploits.[3]

An adversary who is able to obtain unauthorized access to or misuse authorized access to cloud backup services (e.g. Google's Android backup service or Apple's iCloud) could use that access to obtain sensitive data stored in device backups. For example, the Elcomsoft Phone Breaker product advertises the ability to retrieve iOS backup data from Apple's iCloud [1]. Elcomsoft also describes [2] obtaining WhatsApp communication histories from backups stored in iCloud.

Adversaries may abuse odbcconf.exe to proxy execution of malicious payloads. Odbcconf.exe is a Windows utility that allows you to configure Open Database Connectivity (ODBC) drivers and data source names.[1] The Odbcconf.exe binary may be digitally signed by Microsoft.

Adversaries may abuse odbcconf.exe to bypass application control solutions that do not account for its potential abuse. Similar to Regsvr32, odbcconf.exe has a REGSVR flag that can be misused to execute DLLs (ex: odbcconf.exe /S /A {REGSVR "C:\Users\Public\file.dll"}). [2][3][4]

Adversaries may leverage Microsoft Office-based applications for persistence between startups. Microsoft Office is a fairly common application suite on Windows-based operating systems within an enterprise network. There are multiple mechanisms that can be used with Office for persistence when an Office-based application is started; this can include the use of Office Template Macros and add-ins.

A variety of features have been discovered in Outlook that can be abused to obtain persistence, such as Outlook rules, forms, and Home Page.[1] These persistence mechanisms can work within Outlook or be used through Office 365.[2]

Adversaries may abuse Microsoft Office templates to obtain persistence on a compromised system. Microsoft Office contains templates that are part of common Office applications and are used to customize styles. The base templates within the application are used each time an application starts. [1]

Office Visual Basic for Applications (VBA) macros [2] can be inserted into the base template and used to execute code when the respective Office application starts in order to obtain persistence. Examples for both Word and Excel have been discovered and published. By default, Word has a Normal.dotm template created that can be modified to include a malicious macro. Excel does not have a template file created by default, but one can be added that will automatically be loaded.[3][4] Shared templates may also be stored and pulled from remote locations.[5]

Word Normal.dotm location:
C:\Users\<username>\AppData\Roaming\Microsoft\Templates\Normal.dotm

Excel Personal.xlsb location:
C:\Users\<username>\AppData\Roaming\Microsoft\Excel\XLSTART\PERSONAL.XLSB

Adversaries may also change the location of the base template to point to their own by hijacking the application's search order, e.g. Word 2016 will first look for Normal.dotm under C:\Program Files (x86)\Microsoft Office\root\Office16\, or by modifying the GlobalDotName registry key. By modifying the GlobalDotName registry key an adversary can specify an arbitrary location, file name, and file extension to use for the template that will be loaded on application startup. To abuse GlobalDotName, adversaries may first need to register the template as a trusted document or place it in a trusted location.[5]

An adversary may need to enable macros to execute unrestricted depending on the system or enterprise security policy on use of macros.