Command & Control
Malware Update
Detection overview
The "Malware Update" detection focuses on identifying instances where malware within a network is attempting to update itself. Malware often includes mechanisms to connect to command and control (C&C) servers to download updated code, configurations, or additional payloads. Detecting these updates is crucial to prevent the malware from gaining new capabilities, avoiding detection, or executing additional malicious actions.
Triggers
- An internal host is downloading and installing software from the Internet
- The downloads are over HTTP, appear to be machine- driven, and follow a suspicious pattern of checking for availability of files before downloading them
Possible Root Causes
- The initial exploit on this host may be loading malware to continue the attack
- Malware installed on the host may be updating itself to enhance its functionality
- Malware installed on the host may be updating itself to a new version of its software
Business Impact
- An infected host can attack other organizations (e.g. spam, DoS, ad clicks) thus causing harm to your organization’s reputation, potentially causing your IP addresses to be black listed and impacting the performance of business-critical applications
- If this is a targeted attack, it can spread further into your network and ultimately exfiltrate data from it
- The malware which infected the host can create nuisances and affect user productivity
Steps to Verify
- Look up the domain and IP address to which the communication is being sent via reputation services to see if this is known malware; such lookups are supported directly within the UI
- Search for the domain + “virus” via a search engine; this is effective for finding references to known adware or spyware
- Download the supplied PCAP and look at the HTTP payload being sent to see if any data is being leaked in clear text or whether the identity of the program is visible
Malware Update
Possible root causes
Malicious Detection
- An attacker is using C&C servers to update malware on compromised systems.
- Use of automated malware update mechanisms to avoid detection and enhance capabilities.
- Insider threat where an employee has intentionally installed or is updating malware
Benign Detection
- Legitimate software updates that resemble malware activity.
- Security assessments or penetration tests involving controlled malware deployment and updates.
- Misconfigured systems or software causing unusual update behaviors.
Malware Update
Example scenarios
Scenario 1: An internal host starts downloading large files from an external IP address. Further investigation reveals that the files are malware updates downloaded from a command and control server to enhance the malware's capabilities.
Scenario 2: A sudden spike in outbound HTTPS traffic is detected from a server that is normally inactive. Analysis shows that the traffic involves downloading encrypted payloads, indicating an update to an existing malware strain.
Malware Update
Business impact
If this detection indicates a genuine threat, the organization faces significant risks:
Enhanced Malware Capabilities
Updated malware can introduce new functionalities, making it more difficult to detect and remove, and potentially increasing its destructive impact.
Persistent Threat
Regular updates can enable malware to maintain a foothold within the network, continuously evolving to avoid detection and carry out malicious activities.
Data Exfiltration
Updated malware might include new data exfiltration techniques, leading to potential data breaches and loss of sensitive information.
Malware Update
Steps to investigate
Analyze Network Traffic Logs
Review logs for unusual outbound traffic patterns, focusing on connections to known malicious domains or IP addresses and large or frequent downloads.
Inspect the Host
Investigate the internal host generating the suspicious traffic for signs of malware, unauthorized software, or unexpected configurations.
Check for Associated Indicators
Look for other signs of compromise, such as abnormal login attempts, unusual system behavior, or changes in malware signatures.
Consult with IT and Security Teams
Confirm if any authorized software updates or legitimate activities could explain the detected behavior.
Malware Update
MITRE ATT&CK techniques covered
FAQs
What is a malware update?
A malware update involves the process of existing malware connecting to command and control (C&C) servers to download updated code, configurations, or additional payloads, enhancing its capabilities and avoiding detection.
What are the common signs of a malware update?
Signs include connections to suspicious domains, new or modified files in common malware directories, execution of unknown processes, and unusual outbound network traffic.
Can legitimate activities trigger the detection of malware updates?
Yes, legitimate software updates, security assessments, or misconfigured systems can trigger this detection. It’s important to verify the context of the activity.
How does Vectra AI detect malware updates?
Vectra AI uses advanced AI algorithms to analyze network traffic and system changes, identifying patterns indicative of malware updating and correlating these with other suspicious behaviors.
What is the business impact of a malware update?
The primary risks are enhanced malware capabilities, data breaches, operational disruptions, and compliance violations, which can lead to significant harm to the organization.
How can I detect malware updates in my environment?
Monitor network traffic for connections to known or suspicious C&C servers, unusual outbound traffic patterns, and changes in files or processes commonly associated with malware updating.
Why is a malware update a significant threat?
Updated malware can gain new functionalities, making it harder to detect and remove, and can be designed to exfiltrate data more efficiently, leading to data breaches and operational disruptions.
What steps should I take if I detect a malware update?
Investigate the source of the update activity, verify if it was authorized, check for other signs of malicious activity, and take steps to remove the malware and secure affected systems.
What tools can help verify the presence of malware updates?
Tools like network traffic analyzers, security information and event management (SIEM) systems, and specialized malware analysis solutions can help identify and verify malware updates.
How can I prevent malware updates?
Implement strong access controls, monitor network traffic and system changes, use advanced threat detection tools, and regularly audit and update security measures.