SMS Pumping

Executive Summary

SMS Pumping (T1496.003) is a MITRE ATT&CK technique associated with Impact. Adversaries may leverage messaging services for SMS pumping, which may impact system and/or hosted service availability.(Citation: Twilio SMS Pumping) SMS pumping is a type of telecommunications fraud whereby a threat actor first obtains a set of phone numbers from a telecommunications provider, then leverages a victim’s messaging infrastructure to send large amounts of SMS messages to numbers in that set.

Why Attackers Use It

Attackers use SMS Pumping because it provides a reliable way to advance their objective within the Impact tactic, often with a favorable balance of impact versus detectability on SaaS environments. Defenders should assess this behavior in the context of the affected platform and adjacent activity rather than treating it as a standalone indicator.

MITRE Description

Adversaries may leverage messaging services for SMS pumping, which may impact system and/or hosted service availability.(Citation: Twilio SMS Pumping) SMS pumping is a type of telecommunications fraud whereby a threat actor first obtains a set of phone numbers from a telecommunications provider, then leverages a victim’s messaging infrastructure to send large amounts of SMS messages to numbers in that set. By generating SMS traffic to their phone number set, a threat actor may earn payments from the telecommunications provider.(Citation: Twilio SMS Pumping Fraud)

Threat actors often use publicly available web forms, such as one-time password (OTP) or account verification fields, in order to generate SMS traffic. These fields may leverage services such as Twilio, AWS SNS, and Amazon Cognito in the background.(Citation: Twilio SMS Pumping)(Citation: AWS RE:Inforce Threat Detection 2024) In response to the large quantity of requests, SMS costs may increase and communication channels may become overwhelmed.(Citation: Twilio SMS Pumping)

Attack Flow

1. Attacker gains the prerequisite access or context described below.
2. Attacker executes SMS Pumping to achieve its tactical objective (Impact).
3. Resulting access/data/effect is leveraged to advance the broader attack chain (see Related Techniques).

Prerequisites

• Platform(s): SaaS
• ATT&CK does not define one universal permission requirement for this technique. Establish the required access from the observed implementation and affected platform.

Common Tools

• Tool attribution is implementation-specific. Use ATT&CK procedure examples and local telemetry to identify the binaries, services, scripts, accounts, or cloud resources involved.

Commands

No universal command represents SMS Pumping. Capture the exact command line, arguments, parent process, account, host, and execution time from the investigated environment; do not operationalize unverified examples.

Network Traffic

• Network observability is implementation-dependent. Review DNS, proxy, firewall, flow, authentication, and packet telemetry around the activity window, then correlate remote endpoints and protocol behavior with host evidence.

Windows Events

Sysmon Events

Detection Opportunities

No MITRE detection guidance published for this technique.

Relevant ATT&CK Data Sources: N/A

Sigma Rules

A universal Sigma rule would create unreliable results because this technique has no single guaranteed observable. Build detection logic from a documented behavior and supported data source, scope it to the affected platform, and validate it against benign administrative activity before deployment.

Splunk Queries

Start with the data sources named in the detection section. Scope searches by asset, identity, and time window; correlate the primary behavior with preceding access and subsequent actions. A portable query is intentionally not provided where the technique lacks a universal schema or observable.

Investigation Workflow

1. Confirm that the observed behavior is consistent with SMS Pumping and rule out expected administrative or application activity.
2. Establish the first-seen time, initiating identity, source system, target system, and affected resources.
3. Collect relevant host, identity, network, cloud, and application telemetry for the surrounding time window.
4. Correlate parent and child activity, remote connections, file or configuration changes, and related ATT&CK techniques.
5. Determine scope by searching for the same observable across peer assets and identities.
6. Preserve volatile evidence and record confidence, assumptions, and telemetry gaps before containment.

Containment

1. Isolate affected host(s)/account(s) identified during investigation.
2. Revoke or rotate any credentials/tokens potentially exposed.
3. Apply the mitigations listed below where not already enforced.
4. Validate no related techniques (see Related Techniques) were chained against the same asset.

Mitigation

• M1013 -- Application Developer Guidance: Application Developer Guidance focuses on providing developers with the knowledge, tools, and best practices needed to write secure code, reduce vulnerabilities, and implement secure design principles.

Related Techniques

• T1496