Full Report
With our recent release of BiDiBLAH 2.0, we’ve decided to revisit some real world scenarios, and ways BiDiBLAH can deal with it… Herewith, part 2. All the scenarios can be downloaded from the BiDiBLAH home page. Scenario: We have a class B network internally. Many of the users run FTP servers on their machines. We do not allow this – but how do I identify these machines? Solution: Using BiDiBLAH, define your network as netblocks.
Analysis Summary
# Tool/Technique: BiDiBLAH
## Overview
BiDiBLAH is a tool used to analyze network environments, specifically demonstrated here for identifying unauthorized running services (like FTP servers) within a defined network segment (a Class B network) by leveraging port scanning and service banner extraction. It helps defenders or pentesters discover assets that deviate from expected configurations.
## Technical Details
- Type: Tool
- Platform: Implied to be used in a network scanning/analysis context, likely operating system agnostic or targeted toward Windows/Linux environments where the scanning originates.
- Capabilities: Network definition via netblocks, port scanning, service banner extraction, and information retrieval based on service versions.
- First Seen: The article references BiDiBLAH 2.0, suggesting the tool has been around prior to April 2009.
## MITRE ATT&CK Mapping
The scenario described aligns primarily with reconnaissance and discovery actions an adversary (or defender) might take.
- **TA0043 - Discovery**
- **T1046 - Network Service Discovery**
- *Implied focus on identifying active services (FTP on port 21).*
## Functionality
### Core Capabilities
* **Network Definition:** Ability to define the target scope using "netblocks."
* **Port Scanning:** Performing scans across the defined network, specifically targeting port 21/TCP (FTP) in this scenario.
* **Service Fingerprinting:** Extracting service banners from listening ports to identify the software and version running.
### Advanced Features
* **Targeted Information Retrieval:** Ability to search the collected service information (version data) within the tool's "targeting tree" to consolidate and report targeted IP addresses.
## Indicators of Compromise
(Not directly applicable, as BiDiBLAH is presented here as an analytical/scanning utility, not malware. No IOCs are generated by the tool's legitimate use in this context.)
- File Hashes: N/A
- File Names: N/A
- Registry Keys: N/A
- Network Indicators: N/A
- Behavioral Indicators: N/A
## Associated Threat Actors
(Unknown. BiDiBLAH is described as a security tool released by SensePost.)
## Detection Methods
(Detection methods would focus on identifying unauthorized network scanning activity.)
- **Signature-based detection:** Signatures for BiDiBLAH executable or known scan patterns if the tool becomes widely recognized.
- **Behavioral detection:** Detecting rapid, targeted port scanning attempts (especially port 21) followed by traffic indicative of banner grabbing (small, specific data requests and subsequent extractions).
- **YARA rules if available:** N/A
## Mitigation Strategies
* **Prevention measures:** Strict firewall rules preventing non-standard services (like FTP) from listening on internal network interfaces or blocking inbound traffic to port 21/TCP unless explicitly required and only for authorized hosts.
* **Hardening recommendations:** Disabling unnecessary services (like FTP servers) on user workstations or network assets to reduce the attack surface discovered by scanning tools. Implementing network segmentation.
## Related Tools/Techniques
* Nmap (for general port scanning and service identification)
* Other network inventory/discovery tools.