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T1049 System Network Connections Discovery

Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.

An adversary who gains access to a system that is part of a cloud-based environment may map out Virtual Private Clouds or Virtual Networks in order to determine what systems and services are connected. The actions performed are likely the same types of discovery techniques depending on the operating system, but the resulting information may include details about the networked cloud environment relevant to the adversary’s goals. Cloud providers may have different ways in which their virtual networks operate.123 Similarly, adversaries who gain access to network devices may also perform similar discovery activities to gather information about connected systems and services.

Utilities and commands that acquire this information include netstat, “net use,” and “net session” with Net. In Mac and Linux, netstat and lsof can be used to list current connections. who -a and w can be used to show which users are currently logged in, similar to “net session”. Additionally, built-in features native to network devices and Network Device CLI may be used (e.g. show ip sockets, show tcp brief).4

Item Value
ID T1049
Sub-techniques
Tactics TA0007
Platforms IaaS, Linux, Network, Windows, macOS
Version 2.4
Created 31 May 2017
Last Modified 06 September 2022

Procedure Examples

ID Name Description
G0018 admin@338 admin@338 actors used the following command following exploitation of a machine with LOWBALL malware to display network connections: netstat -ano >> %temp%\download88
G0138 Andariel Andariel has used the netstat -naop tcp command to display TCP connections on a victim’s machine.78
G0006 APT1 APT1 used the net use command to get a listing on network connections.62
G0022 APT3 APT3 has a tool that can enumerate current network connections.548687
G0050 APT32 APT32 used the netstat -anpo tcp command to display TCP connections on the victim’s machine.77
G0082 APT38 APT38 installed a port monitoring tool, MAPMAKER, to print the active TCP connections on the local system.82
G0096 APT41 APT41 has enumerated IP addresses of network resources and used the netstat command as part of network reconnaissance. The group has also used a malware variant, HIGHNOON, to enumerate active RDP sessions.7475
S0456 Aria-body Aria-body has the ability to gather TCP and UDP table status listings.26
S0638 Babuk Babuk can use “WNetOpenEnumW” and “WNetEnumResourceW” to enumerate files in network resources for encryption.59
G0135 BackdoorDiplomacy BackdoorDiplomacy has used NetCat and PortQry to enumerate network connections and display the status of related TCP and UDP ports.79
S0089 BlackEnergy BlackEnergy has gathered information about local network connections using netstat.3940
S0335 Carbon Carbon uses the netstat -r and netstat -an commands.25
S0674 CharmPower CharmPower can use netsh wlan show profiles to list specific Wi-Fi profile details.45
G0114 Chimera Chimera has used netstat -ano
S0154 Cobalt Strike Cobalt Strike can produce a sessions report from compromised hosts.30
S0244 Comnie Comnie executes the netstat -ano command.28
S0575 Conti Conti can enumerate routine network connections from a compromised host.55
S0488 CrackMapExec CrackMapExec can discover active sessions for a targeted system.7
S0625 Cuba Cuba can use the function GetIpNetTable to recover the last connections to the victim’s machine.33
S0567 Dtrack Dtrack can collect network and active connection information.15
S0038 Duqu The discovery modules used with Duqu can collect information on network connections.38
G1006 Earth Lusca Earth Lusca employed a PowerShell script called RDPConnectionParser to read and filter the Windows event log “Microsoft-Windows-TerminalServices-RDPClient/Operational”
(Event ID 1024) to obtain network information from RDP connections. Earth Lusca has also used netstat from a compromised system to obtain network connection information.80
S0554 Egregor Egregor can enumerate all connected drives.51
S0363 Empire Empire can enumerate the current network connections of a host.6
S0091 Epic Epic uses the net use, net session, and netstat commands to gather information on network connections.1617
S0696 Flagpro Flagpro has been used to execute netstat -ano on a compromised host.52
C0007 FunnyDream During FunnyDream, the threat actors used netstat to discover network connections on remote systems.93
G0093 GALLIUM GALLIUM used netstat -oan to obtain information about the victim network connections.68
S0237 GravityRAT GravityRAT uses the netstat command to find open ports on the victim’s machine.34
G1001 HEXANE HEXANE has used netstat to monitor connections to specific ports.76
S0283 jRAT jRAT can list network connections.21
G0004 Ke3chang Ke3chang performs local network connection discovery using netstat.8990
S0356 KONNI KONNI has used net session on the victim’s machine.13
S0236 Kwampirs Kwampirs collects a list of active and listening connections by using the command netstat -nao as well as a list of available network mappings with net use.31
G0032 Lazarus Group Lazarus Group has used net use to identify and establish a network connection with a remote host.71
S0681 Lizar Lizar has a plugin to retrieve information about all active network sessions on the infected server.14
S0532 Lucifer Lucifer can identify the IP and port numbers for all remote connections from the compromised host.61
S0409 Machete Machete uses the netsh wlan show networks mode=bssid and netsh wlan show interfaces commands to list all nearby WiFi networks and connected interfaces.24
S1060 Mafalda Mafalda can use the GetExtendedTcpTable function to retrieve information about established TCP connections.53
G0059 Magic Hound Magic Hound has used quser.exe to identify existing RDP connections.66
S0449 Maze Maze has used the “WNetOpenEnumW”, “WNetEnumResourceW”, “WNetCloseEnum” and “WNetAddConnection2W” functions to enumerate the network resources on the infected machine.41
G0045 menuPass menuPass has used net use to conduct connectivity checks to machines.83
S0443 MESSAGETAP After loading the keyword and phone data files, MESSAGETAP begins monitoring all network connections to and from the victim server. 23
G0069 MuddyWater MuddyWater has used a PowerShell backdoor to check for Skype connections on the target machine.65
G0129 Mustang Panda Mustang Panda has used netstat -ano to determine network connection information.67
S0102 nbtstat nbtstat can be used to discover current NetBIOS sessions.
S0039 Net Commands such as net use and net session can be used in Net to gather information about network connections from a particular host.9
S0104 netstat netstat can be used to enumerate local network connections, including active TCP connections and other network statistics.12
S0198 NETWIRE NETWIRE can capture session logon details from a compromised host.37
G0049 OilRig OilRig has used netstat -an on a victim to get a listing of network connections.81
S0439 Okrum Okrum was seen using NetSess to discover NetBIOS sessions.29
C0012 Operation CuckooBees During Operation CuckooBees, the threat actors used the net session, net use, and netstat commands as part of their advanced reconnaissance.92
C0014 Operation Wocao During Operation Wocao, threat actors collected a list of open connections on the infected system using netstat and checks whether it has an internet connection.94
S0165 OSInfo OSInfo enumerates the current network connections similar to net use .54
S0013 PlugX PlugX has a module for enumerating TCP and UDP network connections and associated processes using the netstat command.50
G0033 Poseidon Group Poseidon Group obtains and saves information about victim network interfaces and addresses.91
S0378 PoshC2 PoshC2 contains an implementation of netstat to enumerate TCP and UDP connections.8
S0184 POWRUNER POWRUNER may collect active network connections by running netstat -an on a victim.19
S0192 Pupy Pupy has a built-in utility command for netstat, can do net session through PowerView, and has an interactive shell which can be used to discover additional information.11
S1032 PyDCrypt PyDCrypt has used netsh to find RPC connections on remote machines.43
S0650 QakBot QakBot can use netstat to enumerate current network connections.3635
S0458 Ramsay Ramsay can use netstat to enumerate network connections.27
S0241 RATANKBA RATANKBA uses netstat -ano to search for specific IP address ranges.57
S0153 RedLeaves RedLeaves can enumerate drives and Remote Desktop sessions.56
S0125 Remsec Remsec can obtain a list of active connections and open ports.20
G0034 Sandworm Team Sandworm Team had gathered user, IP address, and server data related to RDP sessions on a compromised host. It has also accessed network diagram files useful for understanding how a host’s network was configured.8584
S0445 ShimRatReporter ShimRatReporter used the Windows function GetExtendedUdpTable to detect connected UDP endpoints.10
S0063 SHOTPUT SHOTPUT uses netstat to list TCP connection status.49
S0589 Sibot Sibot has retrieved a GUID associated with a present LAN connection on a compromised machine.44
S0633 Sliver Sliver can collect network connection information.5
S0533 SLOTHFULMEDIA SLOTHFULMEDIA can enumerate open ports on a victim machine.18
S0374 SpeakUp SpeakUp uses the arp -a command. 47
S0018 Sykipot Sykipot may use netstat -ano to display active network connections.60
G0139 TeamTNT TeamTNT has run netstat -anp to search for rival malware connections.73 TeamTNT has also used libprocesshider to modify /etc/ld.so.preload.72
G0027 Threat Group-3390 Threat Group-3390 has used net use and netstat to conduct internal discovery of systems. The group has also used quser.exe to identify existing RDP sessions on a victim.64
S0678 Torisma Torisma can use WTSEnumerateSessionsW to monitor remote desktop connections.22
S0094 Trojan.Karagany Trojan.Karagany can use netstat to collect a list of network connections.46
G0081 Tropic Trooper Tropic Trooper has tested if the localhost network is available and other connection capability on an infected system using command scripts.32
G0010 Turla Turla surveys a system upon check-in to discover active local network connections using the netstat -an, net use, net file, and net session commands.1669 Turla RPC backdoors have also enumerated the IPv4 TCP connection table via the GetTcpTable2 API call.70
S0452 USBferry USBferry can use netstat and nbtstat to detect active network connections.32
S0180 Volgmer Volgmer can gather information about TCP connection state.58
S0579 Waterbear Waterbear can use API hooks on GetExtendedTcpTable to retrieve a table containing a list of TCP endpoints available to the application.42
S0251 Zebrocy Zebrocy uses netstat -aon to gather network connection information.48

Detection

ID Data Source Data Component
DS0017 Command Command Execution
DS0009 Process OS API Execution

References

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