Input Capture: Web Portal Capture

Adversaries may install code on externally facing portals, such as a VPN login page, to capture and transmit credentials of users who attempt to log into the service. For example, a compromised login page may log provided user credentials before logging the user in to the service.

This variation on input capture may be conducted post-compromise using legitimate administrative access as a backup measure to maintain network access through External Remote Services and Valid Accounts or as part of the initial compromise by exploitation of the externally facing web service.[1]

ID: T1056.003
Sub-technique of:  T1056
Platforms: Linux, Windows, macOS
System Requirements: An externally facing login portal is configured.
Version: 1.0
Created: 11 February 2020
Last Modified: 30 March 2023

Procedure Examples

ID Name Description
S1022 IceApple

The IceApple OWA credential logger can monitor for OWA authentication requests and log the credentials.[2]


ID Mitigation Description
M1026 Privileged Account Management

Do not allow administrator accounts that have permissions to modify the Web content of organization login portals to be used for day-to-day operations that may expose them to potential adversaries on unprivileged systems.


ID Data Source Data Component Detects
DS0022 File File Modification

Monitor for changes made to detect changes to files in the Web directory for organization login pages that do not match with authorized updates to the Web server's content.