Multi-Stage Channels

T1104

Technique.View on attack.mitre.org

About this technique

Adversaries may create multiple stages for command and control that are employed under different conditions or for certain functions. Use of multiple stages may obfuscate the command and control channel to make detection more difficult.

Remote access tools will call back to the first-stage command and control server for instructions. The first stage may have automated capabilities to collect basic host information, update tools, and upload additional files. A second remote access tool (RAT) could be uploaded at that point to redirect the host to the second-stage command and control server. The second stage will likely be more fully featured and allow the adversary to interact with the system through a reverse shell and additional RAT features.

The different stages will likely be hosted separately with no overlapping infrastructure. The loader may also have backup first-stage callbacks or Fallback Channels in case the original first-stage communication path is discovered and blocked.

Detection rules1

Rules on DetectionCode tagged with T1104.

Sigma1

RuleLevelLog source
PowerShell DownloadFilehighwindows / process_creation

Splunk0

No Splunk rules are mapped to this technique yet.

Groups4

Software10

Campaigns1

Procedure examples15

Groups4

Used byProcedure example
GroupAPT3

An APT3 downloader first establishes a SOCKS5 connection to 192.157.198[.]103 using TCP port 1913; once the server response is verified, it then requests a connection to 192.184.60[.]229 on TCP port 81.

GroupAPT41

APT41 used the storescyncsvc.dll BEACON backdoor to download a secondary backdoor.

GroupLazarus Group

Lazarus Group has used multi-stage malware components that inject later stages into separate processes.

GroupMuddyWater

MuddyWater has used one C2 to obtain enumeration scripts and monitor web logs, but a different C2 to send data back.

Software10

Used byProcedure example
MalwareBACKSPACE

BACKSPACE attempts to avoid detection by checking a first stage command and control server to determine if it should connect to the second stage server, which performs "louder" interactions with the malware.

MalwareBazar

The Bazar loader is used to download and execute the Bazar backdoor.

MalwareBLACKCOFFEE

BLACKCOFFEE uses Microsoft’s TechNet Web portal to obtain an encoded tag containing the IP address of a command and control server and then communicates separately with that IP address for C2. If the C2 server is discovered or shut down, the threat actors can update the encoded IP address on TechNet to maintain control of the victims’ machines.

MalwareChaos

After initial compromise, Chaos will download a second stage to establish a more permanent presence on the affected system.

MalwareJumbledPath

JumbledPath can communicate over a unique series of connections to send and retrieve data from exploited devices.

MalwareLatrodectus

Latrodectus has used a two-tiered C2 configuration with tier one nodes connecting to the victim and tier two nodes connecting to backend infrastructure.

MalwareLunarWeb

LunarWeb can use one C2 URL for first contact and to upload information about the host computer and two additional C2 URLs for getting commands.

MalwareSnip3

Snip3 can download and execute additional payloads and modules over separate communication channels.

View all 10 software examples

Campaigns1

Used byProcedure example
CampaignRedPenguin

During RedPenguin, UNC3886 used malware with separate channels to request and carry out tasks from C2.

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