Register to stream ATT&CKcon 2.0 October 29-30

Account Discovery

Adversaries may attempt to get a listing of local system or domain accounts.

Windows

Example commands that can acquire this information are net user, net group , and net localgroup using the Net utility or through use of dsquery. If adversaries attempt to identify the primary user, currently logged in user, or set of users that commonly uses a system, System Owner/User Discovery may apply.

Mac

On Mac, groups can be enumerated through the groups and id commands. In mac specifically, dscl . list /Groups and dscacheutil -q group can also be used to enumerate groups and users.

Linux

On Linux, local users can be enumerated through the use of the /etc/passwd file which is world readable. In mac, this same file is only used in single-user mode in addition to the /etc/master.passwd file.

Also, groups can be enumerated through the groups and id commands.

ID: T1087
Tactic: Discovery
Platform: Linux, macOS, Windows
Permissions Required: User
Data Sources: API monitoring, Process monitoring, Process command-line parameters
CAPEC ID: CAPEC-575
Contributors: Travis Smith, Tripwire
Version: 1.0

Procedure Examples

Name Description
admin@338 admin@338 actors used the following commands following exploitation of a machine with LOWBALL malware to enumerate user accounts: net user >> %temp%\download net user /domain >> %temp%\download [34]
Agent Tesla Agent Tesla collects account information from the victim’s machine. [22]
APT1 APT1 used the commands net localgroup,net user, and net group to find accounts on the system. [40]
APT3 APT3 has used a tool that can obtain info about local and global group users, power users, and administrators. [15]
APT32 APT32 enumerated administrative users and DC servers using the commands net localgroup administrators and net group "Domain Controllers" /domain. [37]
Bankshot Bankshot gathers domain and account names/information through process monitoring. [23]
BRONZE BUTLER BRONZE BUTLER has used net user /domain to identify account information. [38]
Carbon Carbon runs the net group command to list accounts on the system. [12]
Comnie Comnie uses the net user command. [26]
Dragonfly 2.0 Dragonfly 2.0 used batch scripts to enumerate users in the victim environment. [41]
dsquery dsquery can be used to gather information on user accounts within a domain. [6]
Duqu The discovery modules used with Duqu can collect information on accounts and permissions. [9]
Elise Elise executes net user after initial communication is made to the remote server. [29]
Empire Empire can acquire local and domain user account information. [7]
Epic Epic gathers a list of all user accounts, privilege classes, and time of last logon. [20]
FIN6 FIN6 has used Metasploit’s PsExec NTDSGRAB module to obtain a copy of the victim's Active Directory database. [32]
GeminiDuke GeminiDuke collects information on local user accounts from the victim. [25]
InvisiMole InvisiMole has a command to list account information on the victim’s machine. [16]
Kazuar Kazuar gathers information on local groups and members on the victim’s machine. [13]
Ke3chang Ke3chang performs account discovery using commands such as net localgroup administrators and net group "REDACTED" /domain on specific permissions groups. [35]
Kwampirs Kwampirs collects a list of accounts with the command net users. [18]
menuPass menuPass has used the Microsoft administration tool csvde.exe to export Active Directory data. [36]
Mis-Type Mis-Type may create a file containing the results of the command cmd.exe /c net user {Username}. [10]
MURKYTOP MURKYTOP has the capability to retrieve information about users on remote hosts. [14]
Net Commands under net user can be used in Net to gather information about and manipulate user accounts. [2]
OilRig OilRig has run net user, net user /domain, net group “domain admins” /domain, and net group “Exchange Trusted Subsystem” /domain to get account listings on a victim. [39]
OSInfo OSInfo enumerates local and domain users [15]
Poseidon Group Poseidon Group searches for administrator accounts on both the local victim machine and the network. [42]
PoshC2 PoshC2 can enumerate local and domain user account information. [8]
PowerSploit PowerSploit's Get-ProcessTokenGroup Privesc-PowerUp module can enumerate all SIDs associated with its current token. [3] [4]
POWERSTATS POWERSTATS can retrieve usernames from compromised hosts. [19]
POWRUNER POWRUNER may collect user account information by running net user /domain or a series of other commands on a victim. [11]
PUNCHBUGGY PUNCHBUGGY can gather user names. [31]
Pupy Pupy uses PowerView and Pywerview to perform discovery commands such as net user, net group, net local group, etc. [5]
RATANKBA RATANKBA uses the net user command. [21]
Remsec Remsec can obtain a list of users. [30]
S-Type S-Type runs the command net user on a victim. S-Type also runs tests to determine the privilege level of the compromised user. [10]
SHOTPUT SHOTPUT has a command to retrieve information about connected users. [17]
Sykipot Sykipot may use net group "domain admins" /domain to display accounts in the "domain admins" permissions group and net localgroup "administrators" to list local system administrator group membership. [24]
Threat Group-3390 Threat Group-3390 has used net user to conduct internal discovery of systems. [33]
TrickBot TrickBot collects the users of the system. [27] [28]

Mitigations

Mitigation Description
Operating System Configuration Prevent administrator accounts from being enumerated when an application is elevating through UAC since it can lead to the disclosure of account names. The Registry key is located HKLM\ SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\CredUI\EnumerateAdministrators. It can be disabled through GPO: Computer Configuration > [Policies] > Administrative Templates > Windows Components > Credential User Interface: E numerate administrator accounts on elevation. [1]

Detection

System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as Lateral Movement, based on the information obtained.

Monitor processes and command-line arguments for actions that could be taken to gather system and network information. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.

References

  1. UCF. (n.d.). The system must require username and password to elevate a running application.. Retrieved December 18, 2017.
  2. Savill, J. (1999, March 4). Net.exe reference. Retrieved September 22, 2015.
  3. PowerShellMafia. (2012, May 26). PowerSploit - A PowerShell Post-Exploitation Framework. Retrieved February 6, 2018.
  4. PowerSploit. (n.d.). PowerSploit. Retrieved February 6, 2018.
  5. Nicolas Verdier. (n.d.). Retrieved January 29, 2018.
  6. Microsoft. (n.d.). Dsquery. Retrieved April 18, 2016.
  7. Schroeder, W., Warner, J., Nelson, M. (n.d.). Github PowerShellEmpire. Retrieved April 28, 2016.
  8. Nettitude. (2016, June 8). PoshC2: Powershell C2 Server and Implants. Retrieved April 23, 2019.
  9. Symantec Security Response. (2011, November). W32.Duqu: The precursor to the next Stuxnet. Retrieved September 17, 2015.
  10. Gross, J. (2016, February 23). Operation Dust Storm. Retrieved September 19, 2017.
  11. Sardiwal, M, et al. (2017, December 7). New Targeted Attack in the Middle East by APT34, a Suspected Iranian Threat Group, Using CVE-2017-11882 Exploit. Retrieved December 20, 2017.
  12. GovCERT. (2016, May 23). Technical Report about the Espionage Case at RUAG. Retrieved November 7, 2018.
  13. Levene, B, et al. (2017, May 03). Kazuar: Multiplatform Espionage Backdoor with API Access. Retrieved July 17, 2018.
  14. FireEye. (2018, March 16). Suspected Chinese Cyber Espionage Group (TEMP.Periscope) Targeting U.S. Engineering and Maritime Industries. Retrieved April 11, 2018.
  15. Symantec Security Response. (2016, September 6). Buckeye cyberespionage group shifts gaze from US to Hong Kong. Retrieved September 26, 2016.
  16. Hromcová, Z. (2018, June 07). InvisiMole: Surprisingly equipped spyware, undercover since 2013. Retrieved July 10, 2018.
  17. Falcone, R. and Wartell, R.. (2015, July 27). Observations on CVE-2015-3113, Prior Zero-Days and the Pirpi Payload. Retrieved January 22, 2016.
  18. Symantec Security Response Attack Investigation Team. (2018, April 23). New Orangeworm attack group targets the healthcare sector in the U.S., Europe, and Asia. Retrieved May 8, 2018.
  19. Singh, S. et al.. (2018, March 13). Iranian Threat Group Updates Tactics, Techniques and Procedures in Spear Phishing Campaign. Retrieved April 11, 2018.
  20. Kaspersky Lab's Global Research & Analysis Team. (2014, August 06). The Epic Turla Operation: Solving some of the mysteries of Snake/Uroboros. Retrieved November 7, 2018.
  21. Trend Micro. (2017, February 27). RATANKBA: Delving into Large-scale Watering Holes against Enterprises. Retrieved May 22, 2018.
  1. The DigiTrust Group. (2017, January 12). The Rise of Agent Tesla. Retrieved November 5, 2018.
  2. Sherstobitoff, R. (2018, March 08). Hidden Cobra Targets Turkish Financial Sector With New Bankshot Implant. Retrieved May 18, 2018.
  3. Blasco, J. (2011, December 12). Another Sykipot sample likely targeting US federal agencies. Retrieved March 28, 2016.
  4. F-Secure Labs. (2015, September 17). The Dukes: 7 years of Russian cyberespionage. Retrieved December 10, 2015.
  5. Grunzweig, J. (2018, January 31). Comnie Continues to Target Organizations in East Asia. Retrieved June 7, 2018.
  6. Salinas, M., Holguin, J. (2017, June). Evolution of Trickbot. Retrieved July 31, 2018.
  7. Anthony, N., Pascual, C.. (2018, November 1). Trickbot Shows Off New Trick: Password Grabber Module. Retrieved November 16, 2018.
  8. Falcone, R., et al.. (2015, June 16). Operation Lotus Blossom. Retrieved February 15, 2016.
  9. Kaspersky Lab's Global Research & Analysis Team. (2016, August 9). The ProjectSauron APT. Technical Analysis. Retrieved August 17, 2016.
  10. Gorelik, M.. (2019, June 10). SECURITY ALERT: FIN8 IS BACK IN BUSINESS, TARGETING THE HOSPITALITY INDUSTRY. Retrieved June 13, 2019.
  11. FireEye Threat Intelligence. (2016, April). Follow the Money: Dissecting the Operations of the Cyber Crime Group FIN6. Retrieved June 1, 2016.
  12. Counter Threat Unit Research Team. (2017, June 27). BRONZE UNION Cyberespionage Persists Despite Disclosures. Retrieved July 13, 2017.
  13. FireEye Threat Intelligence. (2015, December 1). China-based Cyber Threat Group Uses Dropbox for Malware Communications and Targets Hong Kong Media Outlets. Retrieved December 4, 2015.
  14. Villeneuve, N., Bennett, J. T., Moran, N., Haq, T., Scott, M., & Geers, K. (2014). OPERATION “KE3CHANG”: Targeted Attacks Against Ministries of Foreign Affairs. Retrieved November 12, 2014.
  15. PwC and BAE Systems. (2017, April). Operation Cloud Hopper: Technical Annex. Retrieved April 13, 2017.
  16. Dahan, A. (2017). Operation Cobalt Kitty. Retrieved December 27, 2018.
  17. Counter Threat Unit Research Team. (2017, October 12). BRONZE BUTLER Targets Japanese Enterprises. Retrieved January 4, 2018.
  18. Falcone, R. and Lee, B.. (2016, May 26). The OilRig Campaign: Attacks on Saudi Arabian Organizations Deliver Helminth Backdoor. Retrieved May 3, 2017.
  19. Mandiant. (n.d.). APT1 Exposing One of China’s Cyber Espionage Units. Retrieved July 18, 2016.
  20. US-CERT. (2018, March 16). Alert (TA18-074A): Russian Government Cyber Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved June 6, 2018.
  21. Kaspersky Lab's Global Research and Analysis Team. (2016, February 9). Poseidon Group: a Targeted Attack Boutique specializing in global cyber-espionage. Retrieved March 16, 2016.