Email Collection: Remote Email Collection

Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information. Adversaries may leverage a user's credentials and interact directly with the Exchange server to acquire information from within a network. Adversaries may also access externally facing Exchange services, Office 365, or Google Workspace to access email using credentials or access tokens. Tools such as MailSniper can be used to automate searches for specific keywords.

ID: T1114.002
Sub-technique of:  T1114
Tactic: Collection
Platforms: Google Workspace, Office 365, Windows
Version: 1.2
Created: 19 February 2020
Last Modified: 31 May 2023

Procedure Examples

ID Name Description
G0006 APT1

APT1 uses two utilities, GETMAIL and MAPIGET, to steal email. MAPIGET steals email still on Exchange servers that has not yet been archived.[1]

G0007 APT28

APT28 has collected emails from victim Microsoft Exchange servers.[2][3]

G0016 APT29

APT29 has collected emails from targeted mailboxes within a compromised Azure AD tenant and compromised Exchange servers, including via Exchange Web Services (EWS) API requests.[4][5]

G0114 Chimera

Chimera has harvested data from remote mailboxes including through execution of \\c$\Users\\AppData\Local\Microsoft\Outlook*.ost.[6]

G0035 Dragonfly

Dragonfly has accessed email accounts using Outlook Web Access.[7]

G0085 FIN4

FIN4 has accessed and hijacked online email communications using stolen credentials.[8][9]


HAFNIUM has used web shells to export mailbox data.[10][11]

G0004 Ke3chang

Ke3chang has used compromised credentials and a .NET tool to dump data from Microsoft Exchange mailboxes.[12][13]

G0094 Kimsuky

Kimsuky has used tools such as the MailFetch mail crawler to collect victim emails (excluding spam) from online services via IMAP.[14]

G0077 Leafminer

Leafminer used a tool called MailSniper to search through the Exchange server mailboxes for keywords.[15]

S0395 LightNeuron

LightNeuron collects Exchange emails matching rules specified in its configuration.[16]

G0059 Magic Hound

Magic Hound has exported emails from compromised Exchange servers including through use of the cmdlet New-MailboxExportRequest.[17][18]

S0413 MailSniper

MailSniper can be used for searching through email in Exchange and Office 365 environments.[19]

S0053 SeaDuke

Some SeaDuke samples have a module to extract email from Microsoft Exchange servers using compromised credentials.[20]

C0024 SolarWinds Compromise

During the SolarWinds Compromise, APT29 collected emails from specific individuals, such as executives and IT staff, using New-MailboxExportRequest followed by Get-MailboxExportRequest.[21][22]

S0476 Valak

Valak can collect sensitive mailing information from Exchange servers, including credentials and the domain certificate of an enterprise.[23]


ID Mitigation Description
M1041 Encrypt Sensitive Information

Use of encryption provides an added layer of security to sensitive information sent over email. Encryption using public key cryptography requires the adversary to obtain the private certificate along with an encryption key to decrypt messages.

M1032 Multi-factor Authentication

Use of multi-factor authentication for public-facing webmail servers is a recommended best practice to minimize the usefulness of usernames and passwords to adversaries.


ID Data Source Data Component Detects
DS0015 Application Log Application Log Content

In Office365 environments, consider using PurviewAudit to collect MailItemsAccessed events and monitoring for unusual email access behavior.[24]

DS0017 Command Command Execution

Monitor executed commands and arguments for actions that may target an Exchange server, Office 365, or Google Workspace to collect sensitive information.

DS0028 Logon Session Logon Session Creation

Monitor for unusual login activity from unknown or abnormal locations, especially for privileged accounts (ex: Exchange administrator account).

DS0029 Network Traffic Network Connection Creation

Monitor for newly constructed network connections that are sent or received by untrusted hosts.


  1. Mandiant. (n.d.). APT1 Exposing One of China’s Cyber Espionage Units. Retrieved July 18, 2016.
  2. Mueller, R. (2018, July 13). Indictment - United States of America vs. VIKTOR BORISOVICH NETYKSHO, et al. Retrieved September 13, 2018.
  3. NSA, CISA, FBI, NCSC. (2021, July). Russian GRU Conducting Global Brute Force Campaign to Compromise Enterprise and Cloud Environments. Retrieved July 26, 2021.
  4. Douglas Bienstock. (2022, August 18). You Can’t Audit Me: APT29 Continues Targeting Microsoft 365. Retrieved February 23, 2023.
  5. Mandiant. (2022, May 2). UNC3524: Eye Spy on Your Email. Retrieved August 17, 2023.
  6. Jansen, W . (2021, January 12). Abusing cloud services to fly under the radar. Retrieved January 19, 2021.
  7. US-CERT. (2018, March 16). Alert (TA18-074A): Russian Government Cyber Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved June 6, 2018.
  8. Vengerik, B. et al.. (2014, December 5). Hacking the Street? FIN4 Likely Playing the Market. Retrieved December 17, 2018.
  9. Vengerik, B. & Dennesen, K.. (2014, December 5). Hacking the Street? FIN4 Likely Playing the Market. Retrieved January 15, 2019.
  10. MSTIC. (2021, March 2). HAFNIUM targeting Exchange Servers with 0-day exploits. Retrieved March 3, 2021.
  11. Gruzweig, J. et al. (2021, March 2). Operation Exchange Marauder: Active Exploitation of Multiple Zero-Day Microsoft Exchange Vulnerabilities. Retrieved March 3, 2021.
  12. Smallridge, R. (2018, March 10). APT15 is alive and strong: An analysis of RoyalCli and RoyalDNS. Retrieved April 4, 2018.