Man in the Browser

Adversaries can take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify behavior, and intercept information as part of various man in the browser techniques. [1]

A specific example is when an adversary injects software into a browser that allows an them to inherit cookies, HTTP sessions, and SSL client certificates of a user and use the browser as a way to pivot into an authenticated intranet. [2] [3]

Browser pivoting requires the SeDebugPrivilege and a high-integrity process to execute. Browser traffic is pivoted from the adversary's browser through the user's browser by setting up an HTTP proxy which will redirect any HTTP and HTTPS traffic. This does not alter the user's traffic in any way. The proxy connection is severed as soon as the browser is closed. Whichever browser process the proxy is injected into, the adversary assumes the security context of that process. Browsers typically create a new process for each tab that is opened and permissions and certificates are separated accordingly. With these permissions, an adversary could browse to any resource on an intranet that is accessible through the browser and which the browser has sufficient permissions, such as Sharepoint or webmail. Browser pivoting also eliminates the security provided by 2-factor authentication. [4]

ID: T1185
Sub-techniques:  No sub-techniques
Tactic: Collection
Platforms: Windows
Permissions Required: Administrator, SYSTEM
Data Sources: Logon Session: Logon Session Creation, Process: Process Access
Contributors: Justin Warner, ICEBRG
Version: 1.0
Created: 16 January 2018
Last Modified: 09 February 2021

Procedure Examples

ID Name Description
S0331 Agent Tesla

Agent Tesla has the ability to use form-grabbing to extract data from web data forms.[5]

S0484 Carberp

Carberp has captured credentials when a user performs login through a SSL session.[6][7]

S0154 Cobalt Strike

Cobalt Strike can perform browser pivoting and inject into a user's browser to inherit cookies, authenticated HTTP sessions, and client SSL certificates.[4]

S0384 Dridex

Dridex can perform browser attacks via web injects to steal information such as credentials, certificates, and cookies.[8]

S0531 Grandoreiro

Grandoreiro can monitor browser activity for online banking actions and display full-screen overlay images to block user access to the intended site or present additional data fields.[9][10][11]

S0483 IcedID

IcedID has used web injection attacks to redirect victims to spoofed sites designed to harvest banking and other credentials. IcedID can use a self signed TLS certificate in connection with the spoofed site and simultaneously maintains a live connection with the legitimate site to display the correct URL and certificates in the browser.[12][13]

S0530 Melcoz

Melcoz can monitor the victim's browser for online banking sessions and display an overlay window to manipulate the session in the background.[9]

S0266 TrickBot

TrickBot uses web injects and browser redirection to trick the user into providing their login credentials on a fake or modified web page.[14][15][16][17]

S0386 Ursnif

Ursnif has injected HTML codes into banking sites to steal sensitive online banking information (ex: usernames and passwords).[18]


ID Mitigation Description
M1018 User Account Management

Since browser pivoting requires a high integrity process to launch from, restricting user permissions and addressing Privilege Escalation and Bypass User Account Control opportunities can limit the exposure to this technique.

M1017 User Training

Close all browser sessions regularly and when they are no longer needed.


This is a difficult technique to detect because adversary traffic would be masked by normal user traffic. No new processes are created and no additional software touches disk. Authentication logs can be used to audit logins to specific web applications, but determining malicious logins versus benign logins may be difficult if activity matches typical user behavior. Monitor for process injection against browser applications.