Full Report
Today at BlackHat USA 2010 we released a tool for manipulating memcached instances; we still need to write it up properly but here’s a link to the tool for the moment. tl;dr: if you find a memcached, you can dump the cache and manipulate entries in the cache.
Analysis Summary
# Tool/Technique: Go-derper
## Overview
Go-derper is a tool released at BlackHat USA 2010, designed to interact with and manipulate memcached instances discovered on a network. Its primary purpose is to allow an attacker to dump the contents of a memcached cache and modify the stored entries.
## Technical Details
- Type: Tool
- Platform: Unspecified (Assumed to target systems running memcached services, typically Linux/Unix-like environments, though the tool itself may run on any platform capable of network interaction).
- Capabilities: Dumping cache entries, manipulating cache entries.
- First Seen: BlackHat USA 2010 (July 2010).
## MITRE ATT&CK Mapping
The immediate actions performed by this tool map primarily to Discovery and Collection phases related to accessing vulnerable services.
- **TA0007 - Discovery**
- **T1046 - Network Service Scanning** (If used to scan endpoints to find open memcached ports)
- **TA0009 - Collection**
- **T1537 - Data from Local System** (If the retrieved data is considered sensitive configuration or session data stored in memory/cache)
- **T1005 - Data from Local System** (Implied data staging/exfiltration of collected data)
## Functionality
### Core Capabilities
- **Cache Dumping:** Retrieving the entire contents (key-value pairs) stored within a running memcached instance.
- **Cache Manipulation:** Modifying existing entries stored in the cache.
### Advanced Features
The description is brief, suggesting a specialized utility focused solely on the memcached protocol manipulation rather than broad framework capabilities. Its advanced nature lies in directly targeting and altering ephemeral, in-memory data stores often overlooked by traditional security monitoring.
## Indicators of Compromise
As this is a proof-of-concept (PoC) or specialized utility, standard malware IoCs are unlikely unless repurposed or embedded.
- File Hashes: N/A (Link provided points to a tool download, hashes not listed in the source).
- File Names: `go-derper` (Likely, based on the tool name).
- Registry Keys: N/A
- Network Indicators: Connections utilizing the default memcached port (typically **11211/TCP**).
- Behavioral Indicators: Unauthenticated attempts to execute `get`, `set`, `delete`, or similar commands against a memcached service endpoint.
## Associated Threat Actors
This specific tool, Go-derper, appears to be a publicly released security proof-of-concept rather than a dedicated exploit used by known advanced persistent threat (APT) groups, although the underlying technique (memcached abuse) is well-known.
## Detection Methods
- Signature-based detection: Signatures for the specific binary `go-derper`.
- Behavioral detection: Monitoring network traffic for clients connecting to memcached ports (often plaintext) performing a high volume of `get`, `set`, or `flush_all` operations from unexpected hosts.
- YARA rules: Potential rules targeting binary strings or imports indicative of a Go-compiled network utility focused on the memcached protocol.
## Mitigation Strategies
- Prevention: Never expose memcached instances directly to the public internet. If internal access is required, strictly enforce network ACLs.
- Hardening recommendations: Deploy memcached instances within a protected network segment, preferably using authentication mechanisms or proxy layers if external access patterns are unavoidable (though memcached natively lacks robust authentication). Ensure regular cache flushing mechanisms are in place if sensitive data is stored.
## Related Tools/Techniques
- Memcached Injection/Abuse: The general technique of exploiting insecurely configured memcached servers to potentially hijack sessions, poison caches, or exploit resulting application logic flaws.
- Other memcached scanning/exploitation tools.