{ "family": "redsip", "sample_count": 1, "category": "trojan", "description": "

Executive Summary

\nRedSip is a highly specialized Trojan and backdoor designed specifically to target, intercept, and exploit Voice over IP (VoIP) communications, specifically focusing on the SIP (Session Initiation Protocol). Rather than stealing standard files, RedSip operates as an espionage tool, aiming to monitor telephone communications, steal SIP credentials, and potentially facilitate toll fraud by routing unauthorized calls through the compromised corporate PBX infrastructure.\n\n

Infection Vector and Technical Capabilities

\nRedSip typically infects softphone clients (software-based VoIP phones) running on Windows endpoints. The initial vector is often a targeted phishing attack or the deployment of a secondary payload by an initial access broker.\n\nOnce active, RedSip focuses exclusively on VoIP espionage:\n\n\n

Threat Assessment

\nA RedSip infection is a critical security and financial incident. It represents a severe breach of corporate communications privacy and poses a direct, immediate financial threat through the facilitation of toll fraud (PBX hacking).\n\n

Incident Response and Remediation

\n", "cta": "Published by the SystemHelpdesk team.", "aliases": [ "Trojan.RedSip", "Spyware.SIP", "Backdoor.RedSip", "TollFraud.Win32" ], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Redsip and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Redsip is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments." } }, { "@type": "Question", "name": "How does Redsip establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Redsip typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks." } }, { "@type": "Question", "name": "What are the essential incident response steps for mitigating a Redsip compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Redsip should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups." } }, { "@type": "Question", "name": "What secondary payloads and staging behaviors are commonly associated with Trojan.RedSip?", "acceptedAnswer": { "@type": "Answer", "text": "Trojan.RedSip frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors." } }, { "@type": "Question", "name": "How can security operations teams effectively detect and hunt for Trojan.RedSip across enterprise endpoints?", "acceptedAnswer": { "@type": "Answer", "text": "Defenders should hunt for Trojan.RedSip by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries." } } ], "faq_count": 5, "mitre_attack": [ "T1555.003", "T1040", "T1056.001" ], "cisa_advisory": null, "last_updated": "2026-10-15", "type": "Trojan / VoIP Spyware", "target_industries": [ "Global / Opportunistic" ], "motivation": "Opportunistic", "threat_actors": [ "Unknown / Cybercriminal" ], "target_geographies": [ "Global" ], "attack_stage": [ "execution", "persistence" ], "ecosystem": [ "windows_pe" ], "is_emerging": false, "mitre_attack_detail": [ { "id": "T1555.003", "name": "Credentials from Web Browsers", "tactic": "Unknown" }, { "id": "T1040", "name": "Network Sniffing (Stealing credentials in transit)", "tactic": "Credential Access" }, { "id": "T1056.001", "name": "Keylogging", "tactic": "Credential Access" } ], "containment_steps": [ "Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Redsip from retrieving secondary stage payloads.", "Capture process memory triage to detect and terminate malicious threads injected by Redsip into legitimate system processes such as explorer.exe or svchost.exe.", "Audit Windows Registry Run keys (HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Run) and Task Scheduler entries to locate and purge Redsip persistence hooks.", "Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.", "Rotate all credentials, domain user passwords, and session cookies active on the system during the Redsip execution timeframe." ], "what_to_avoid": [ "Do not assume the incident is resolved simply because an antivirus tool removed the initial Redsip dropper; always verify that secondary payloads and persistence hooks have been eradicated.", "Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Redsip until memory triage is complete.", "Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution." ], "target_platforms": [ "Windows 11", "Windows 10", "Windows 7" ] }