Executive Summary

• SGI sensors detected a suspicious JavaScript framework originating from IP address 51.159.199.236 (France).
• The framework, identified as ‘standalone-framework.js’, exhibits low VirusTotal detection rates despite containing potentially suspicious components.
• The likely objective is reconnaissance, code injection, or client-side data theft, given the nature of JavaScript frameworks.
• The business risk is moderate due to the potential for website compromise and data breaches.
• Organizations should review the provided IoCs and ensure web application security best practices are followed to prevent potential exploitation.

We anticipate an increase in client-side attacks leveraging obfuscated JavaScript within the next quarter, making proactive monitoring essential.

Observed Activity (SGI Sensors)

SGI sensors detected network activity originating from 51.159.199.236, associated with AS12876 (SCALEWAY S.A.S.) in France. The traffic was TCP based, and included a JavaScript payload identified as ‘standalone-framework.js’. The low detection rate on VirusTotal suggests either a novel threat or effective obfuscation techniques. Further investigation is warranted to understand the full scope and potential impact of this activity.

Malware/Technique Overview

The detected malware family is ‘standalone-framework.js’. Given the nature of JavaScript frameworks, it could be used for various malicious purposes, including:

• Keylogging and form grabbing
• Credential harvesting
• Website defacement or redirection
• Remote code execution (if vulnerabilities are present)

The initial access vector is likely through compromised websites or malicious advertisements (malvertising). Targets are end-users visiting these compromised sites.

MITRE ATT&CK Mapping:

• T1189 – Drive-by Compromise
• T1059.007 – Command and Scripting Interpreter: JavaScript
• T1555.003 – Credentials from Password Stores: Web Browser Credential Storage
• T1190 – Exploit Public-Facing Application

VirusTotal Snapshot

VirusTotal analysis shows low detection rates, with 0 vendors flagging the sample as malicious and 62 reporting it as undetected. The sample is identified as Text.

Notable file names found as aliases include ‘__init__.py’, ‘aes-js-l0sNRNKZ.js’, and ‘proguard-rules.pro’.

• VirusTotal Sample

Indicators of Compromise (IoCs)

Recommendation: Monitor these IoCs for at least 30 days.

Detection & Hunting

Splunk SPL:

index=* src_ip=51.159.199.0/24  (SHA256_HASH=01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b OR file_name="standalone-framework.js")
| table _time, src_ip, dest_ip, file_name, SHA256_HASH

Elastic/Kibana KQL:

source.ip : 51.159.199.0/24 AND (file.hash.sha256 : "01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b" OR file.name : "standalone-framework.js")

Guidance: Validate true positives by examining network connections and user behavior patterns. False positives might occur due to legitimate JavaScript frameworks, so context is crucial.

Containment, Eradication & Recovery

1. Isolate: Immediately isolate any affected systems from the network to prevent further spread.
2. Block: Block the identified IP address (51.159.199.XXX) at the firewall level.
3. Scan: Perform a full malware scan on all potentially affected systems using updated antivirus software.
4. Reimage: If systems are heavily infected, reimage them from a known good backup.
5. Reset Credentials: Reset passwords for all accounts that may have been compromised.

Communication Plan: Inform IT and leadership teams about the incident and remediation steps. Prepare a communication plan if customer data is potentially at risk.

Evidence Preservation: Preserve system logs, network traffic captures, and memory dumps for forensic analysis.

Hardening & Preventive Controls

• Multi-Factor Authentication (MFA): Implement MFA for all critical accounts (NIST CSF PR.AC-1, CIS Control 6).
• Endpoint Detection and Response (EDR): Tune EDR solutions to detect and block suspicious JavaScript activity (NIST CSF DE.CM-7, CIS Control 10).
• Network Segmentation: Segment the network to limit the lateral movement of attackers (NIST CSF PR.AC-4, CIS Control 14).
• Least Privilege: Enforce the principle of least privilege to limit user access rights (NIST CSF PR.AC-3, CIS Control 5).
• Patch SLAs: Establish and enforce SLAs for patching vulnerabilities in web applications and browsers (NIST CSF PR.PT-1, CIS Control 7).

Business Impact & Risk Outlook

The potential business impact includes:

• Operational Disruption: Website downtime and service interruptions.
• Legal Liability: Potential fines and lawsuits if customer data is compromised.
• Reputational Damage: Loss of customer trust and negative media coverage.

Forward-Looking Trend: We anticipate an increase in sophisticated client-side attacks leveraging obfuscated JavaScript frameworks. Organizations need to prioritize web application security and implement robust monitoring and detection mechanisms.

Appendix

Assumptions & Data Gaps:

• We assume the ‘standalone-framework.js’ file is malicious based on its detection and the originating IP address.
• We lack the specific purpose and functionality of the JavaScript framework due to limited VirusTotal detections.
• The affected applications are unknown, thus hardening measures should be applied broadly.

• VirusTotal Sample

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