Wordlist Scanning

Executive Summary

Wordlist Scanning (T1595.003) is a MITRE ATT&CK technique associated with Reconnaissance. Adversaries may iteratively probe infrastructure using brute-forcing and crawling techniques.

Why Attackers Use It

Attackers use Wordlist Scanning because it provides a reliable way to advance their objective within the Reconnaissance tactic, often with a favorable balance of impact versus detectability on PRE 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 iteratively probe infrastructure using brute-forcing and crawling techniques. While this technique employs similar methods to Brute Force, its goal is the identification of content and infrastructure rather than the discovery of valid credentials. Wordlists used in these scans may contain generic, commonly used names and file extensions or terms specific to a particular software. Adversaries may also create custom, target-specific wordlists using data gathered from other Reconnaissance techniques (ex: Gather Victim Org Information, or Search Victim-Owned Websites).

For example, adversaries may use web content discovery tools such as Dirb, DirBuster, and GoBuster and generic or custom wordlists to enumerate a website’s pages and directories.(Citation: ClearSky Lebanese Cedar Jan 2021) This can help them to discover old, vulnerable pages or hidden administrative portals that could become the target of further operations (ex: Exploit Public-Facing Application or Brute Force).

As cloud storage solutions typically use globally unique names, adversaries may also use target-specific wordlists and tools such as s3recon and GCPBucketBrute to enumerate public and private buckets on cloud infrastructure.(Citation: S3Recon GitHub)(Citation: GCPBucketBrute) Once storage objects are discovered, adversaries may leverage Data from Cloud Storage to access valuable information that can be exfiltrated or used to escalate privileges and move laterally.

Attack Flow

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

Prerequisites

• Platform(s): PRE
• 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 Wordlist Scanning. 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 Wordlist Scanning 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

• M1042 -- Disable or Remove Feature or Program: Disable or remove unnecessary and potentially vulnerable software, features, or services to reduce the attack surface and prevent abuse by adversaries.
• M1056 -- Pre-compromise: Pre-compromise mitigations involve proactive measures and defenses implemented to prevent adversaries from successfully identifying and exploiting weaknesses during the Reconnaissance and Resource Development phases of an attack.

Related Techniques

• T1595