COMMON ATTACK PATTERN ENUMERATION AND CLASSIFICATIONLive MITRE record

CAPEC-701

Browser in the Middle (BiTM)

An adversary exploits the inherent functionalities of a web browser, in order to establish an unnoticed remote desktop connection in the victim's browser to the adversary's system. The adversary must deploy a web client with a remote desktop session that the victim can access.

Abstraction

Standard

Typical severity

High

Likelihood of attack

Medium

Understand the attack

What is this attack pattern?

An adversary exploits the inherent functionalities of a web browser, in order to establish an unnoticed remote desktop connection in the victim's browser to the adversary's system. The adversary must deploy a web client with a remote desktop session that the victim can access.

Extended description

Unlike Adversary in the Browser, the victim does not need to install a malicious application. Browser in the Middle uses the inherent functionalities of a web browser to convince the victim they are browsing normally under the assumption that the connection is secure. All the actions performed by the victim in the open window are actually performed on the machine of the adversary. These victim-authenticated sessions are available to the adversary to use. All entered data such as passwords and usernames can be logged by the adversary and the content displayed to the victim can be altered arbitrarily. Varieties of multifactor authentication which rely solely on user input and do not use a form of hardware-based secret exchange are vulnerable to browser in the middle.

Execution flow

How does the attack proceed, step by step?

1

Explore

Identify potential targets

The adversary identifies an application or service that the target is likely to use.

Techniques used

  • The adversary stands up a server to host the transparent browser and entices victims to use it by using a domain name similar to the legitimate application. In addition to the transparent browser, the adversary could also install a web proxy, sniffer, keylogger, and other tools to assist in their goals.
2

Experiment

Lure victims

The adversary crafts a phishing campaign to lure unsuspecting victims into using the transparent browser.

Techniques used

  • An adversary can create a convincing email with a link to download the web client and interact with the transparent browser.
3

Exploit

Monitor and Manipulate Data

When the victim establishes the connection to the transparent browser, the adversary can view victim activity and make alterations to what the victim sees when browsing the web.

Techniques used

  • Once a victim has established a connection to the transparent browser, the adversary can use installed tools such as a web proxy, keylogger, or additional malicious browser extensions to gather and manipulate data or impersonate the victim.

Requirements

What does the attack require?

Prerequisites

  • The adversary must create a convincing web client to establish the connection. The victim then needs to be lured onto the adversary's webpage. In addition, the victim's machine must not use local authentication APIs, a hardware token, or a Trusted Platform Module (TPM) to authenticate.

Skills required

Not stated in the MITRE record.

Resources required

  • A web application with a client is needed to enable the victim's browser to establish a remote desktop connection to the system of the adversary.

Impact

What does a successful attack lead to?

Gain Privileges

Affected scopes: Confidentiality, Access Control, Authentication

Likelihood: High

Read Data

Affected scopes: Confidentiality, Authorization

Likelihood: High

Modify Data

Affected scopes: Integrity

Likelihood: Medium

Defence

How is it prevented and mitigated?

1
Implementation: Use strong, mutual authentication to fully authenticate with both ends of any communications channel