Gather Victim Identity Information: Email Addresses

Adversaries may gather email addresses that can be used during targeting. Even if internal instances exist, organizations may have public-facing email infrastructure and addresses for employees.

Adversaries may easily gather email addresses, since they may be readily available and exposed via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites).[1][2] Email addresses could also be enumerated via more active means (i.e. Active Scanning), such as probing and analyzing responses from authentication services that may reveal valid usernames in a system.[3] For example, adversaries may be able to enumerate email addresses in Office 365 environments by querying a variety of publicly available API endpoints, such as autodiscover and GetCredentialType.[4][5]

Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Phishing for Information), establishing operational resources (ex: Email Accounts), and/or initial access (ex: Phishing or Brute Force via External Remote Services).

ID: T1589.002
Sub-technique of:  T1589
Tactic: Reconnaissance
Platforms: PRE
Contributors: Jannie Li, Microsoft Threat Intelligence Center (MSTIC)
Version: 1.2
Created: 02 October 2020
Last Modified: 21 October 2022

Procedure Examples

ID Name Description
S0677 AADInternals

AADInternals can check for the existence of user email addresses using public Microsoft APIs.[6][7]

G0050 APT32

APT32 has collected e-mail addresses for activists and bloggers in order to target them with spyware.[8]

G1011 EXOTIC LILY

EXOTIC LILY has gathered targeted individuals' e-mail addresses through open source research and website contact forms.[9]

G0125 HAFNIUM

HAFNIUM has collected e-mail addresses for users they intended to target.[10]

G1001 HEXANE

HEXANE has targeted executives, human resources staff, and IT personnel for spearphishing.[11][12]

G0094 Kimsuky

Kimsuky has collected valid email addresses including personal accounts that were subsequently used for spearphishing and other forms of social engineering.[13][14]

G1004 LAPSUS$

LAPSUS$ has gathered employee email addresses, including personal accounts, for social engineering and initial access efforts.[15]

G0032 Lazarus Group

Lazarus Group collected email addresses belonging to various departments of a targeted organization which were used in follow-on phishing campaigns.[16]

G0059 Magic Hound

Magic Hound has identified high-value email accounts in academia, journalism, NGO's, foreign policy, and national security for targeting.[17][18]

G1036 Moonstone Sleet

Moonstone Sleet gathered victim email address information for follow-on phishing activity.[19]

G1031 Saint Bear

Saint Bear gathered victim email information in advance of phishing operations for targeted attacks.[20]

G0034 Sandworm Team

Sandworm Team has obtained valid emails addresses while conducting research against target organizations that were subsequently used in spearphishing campaigns.[21]

G0122 Silent Librarian

Silent Librarian has collected e-mail addresses from targeted organizations from open Internet searches.[22]

G0127 TA551

TA551 has used spoofed company emails that were acquired from email clients on previously infected hosts to target other individuals.[23]

G1017 Volt Typhoon

Volt Typhoon has targeted the personal emails of key network and IT staff at victim organizations.[24]

C0037 Water Curupira Pikabot Distribution

Water Curupira Pikabot Distribution utilizes thread spoofing of existing email threads in order to execute spear phishing operations.[25]

Mitigations

ID Mitigation Description
M1056 Pre-compromise

This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls. Efforts should focus on minimizing the amount and sensitivity of data available to external parties.

Detection

ID Data Source Data Component Detects
DS0029 Network Traffic Network Traffic Content

Monitor for suspicious network traffic that could be indicative of probing for email addresses and/or usernames, such as large/iterative quantities of authentication requests originating from a single source (especially if the source is known to be associated with an adversary/botnet). Analyzing web metadata may also reveal artifacts that can be attributed to potentially malicious activity, such as referer or user-agent string HTTP/S fields.

References

  1. Hackers Arise. (n.d.). Email Scraping and Maltego. Retrieved October 20, 2020.
  2. Ng, A. (2019, January 17). Massive breach leaks 773 million email addresses, 21 million passwords. Retrieved October 20, 2020.
  3. GrimHacker. (2017, July 24). Office365 ActiveSync Username Enumeration. Retrieved December 9, 2021.
  4. gremwell. (2020, March 24). Office 365 User Enumeration. Retrieved May 27, 2022.
  5. Dr. Nestori Syynimaa. (2020, June 13). Just looking: Azure Active Directory reconnaissance as an outsider. Retrieved May 27, 2022.
  6. Dr. Nestori Syynimaa. (2018, October 25). AADInternals. Retrieved February 18, 2022.
  7. Dr. Nestori Syynimaa. (2020, June 13). Just looking: Azure Active Directory reconnaissance as an outsider. Retrieved February 1, 2022.
  8. Amnesty International. (2021, February 24). Vietnamese activists targeted by notorious hacking group. Retrieved March 1, 2021.
  9. Stolyarov, V. (2022, March 17). Exposing initial access broker with ties to Conti. Retrieved August 18, 2022.
  10. Gruzweig, J. et al. (2021, March 2). Operation Exchange Marauder: Active Exploitation of Multiple Zero-Day Microsoft Exchange Vulnerabilities. Retrieved March 3, 2021.
  11. SecureWorks 2019, August 27 LYCEUM Takes Center Stage in Middle East Campaign Retrieved. 2019/11/19
  12. ClearSky Cyber Security . (2021, August). New Iranian Espionage Campaign By “Siamesekitten” - Lyceum. Retrieved June 6, 2022.
  13. Jazi, H. (2021, June 1). Kimsuky APT continues to target South Korean government using AppleSeed backdoor. Retrieved June 10, 2021.
  1. Lesnewich, G. et al. (2024, April 16). From Social Engineering to DMARC Abuse: TA427’s Art of Information Gathering. Retrieved May 3, 2024.
  2. MSTIC, DART, M365 Defender. (2022, March 24). DEV-0537 Criminal Actor Targeting Organizations for Data Exfiltration and Destruction. Retrieved May 17, 2022.
  3. Vyacheslav Kopeytsev and Seongsu Park. (2021, February 25). Lazarus targets defense industry with ThreatNeedle. Retrieved October 27, 2021.
  4. Miller, J. et al. (2021, July 13). Operation SpoofedScholars: A Conversation with TA453. Retrieved August 18, 2021.
  5. Bash, A. (2021, October 14). Countering threats from Iran. Retrieved January 4, 2023.
  6. Microsoft Threat Intelligence. (2024, May 28). Moonstone Sleet emerges as new North Korean threat actor with new bag of tricks. Retrieved August 26, 2024.
  7. Unit 42. (2022, February 25). Spear Phishing Attacks Target Organizations in Ukraine, Payloads Include the Document Stealer OutSteel and the Downloader SaintBot. Retrieved June 9, 2022.
  8. Scott W. Brady. (2020, October 15). United States vs. Yuriy Sergeyevich Andrienko et al.. Retrieved November 25, 2020.
  9. DOJ. (2018, March 23). U.S. v. Rafatnejad et al . Retrieved February 3, 2021.
  10. Duncan, B. (2021, January 7). TA551: Email Attack Campaign Switches from Valak to IcedID. Retrieved March 17, 2021.
  11. CISA et al.. (2024, February 7). PRC State-Sponsored Actors Compromise and Maintain Persistent Access to U.S. Critical Infrastructure. Retrieved May 15, 2024.
  12. Shinji Robert Arasawa, Joshua Aquino, Charles Steven Derion, Juhn Emmanuel Atanque, Francisrey Joshua Castillo, John Carlo Marquez, Henry Salcedo, John Rainier Navato, Arianne Dela Cruz, Raymart Yambot & Ian Kenefick. (2024, January 9). Black Basta-Affiliated Water Curupira’s Pikabot Spam Campaign. Retrieved July 17, 2024.