This week’s threat intelligence roundup showcases the growing sophistication of post-exploitation techniques, with three notable cases revealing how attackers maintain persistence and escalate access after breaching initial defenses.
A high-impact supply-chain breach at Allianz Life was enabled by compromised access to a third-party CRM provider, revealing the growing vulnerability of vendor ecosystems.
Meanwhile, Ghost Calls emerged as a stealthy new method for abusing conferencing platforms to conduct command-and-control activity undetected. Finally, Microsoft issued urgent guidance for a privilege escalation flaw in hybrid Exchange environments, underscoring risks tied to identity federation.
Here’s what security teams need to know.
Allianz Life Breach: Third-Party Access Enables Post-Exploitation Data Theft
On July 16, 2025, Allianz Life Insurance Company of North America suffered a breach through a third-party vendor responsible for managing its CRM platform.
Threat actors used social engineering to access the CRM platform, compromising personal data of approximately 1.4 million U.S. customers, financial professionals, and some employees. The exposed data included names, addresses, dates of birth, and confirmed Social Security numbers.
Allianz’s internal systems were not compromised, according to public disclosures, and the company reported the incident to the FBI. Affected individuals are being offered identity protection and credit monitoring services.
While attribution has not been officially confirmed, security researchers suspect the involvement of well-known cybercriminal groups operating in the supply-chain threat space. The breach highlights the critical impact of third-party risk and the speed at which attackers can move from vendor to enterprise data.
This incident exemplifies the increasingly sophisticated nature of post-exploitation techniques in modern supply-chain attacks. The adversaries did not need to penetrate Allianz’s primary infrastructure.
Instead, they leveraged trusted third-party access as an initial foothold, then escalated their reach to sensitive client data. This layered approach illustrates the critical need for continuous visibility into vendor environments, strict access controls for external integrations, and rigorous incident response planning that includes partners and suppliers.
Moreover, the attack underscores the importance of robust authentication and segmentation policies. Organizations must not only audit their internal defenses but also scrutinize the security posture of connected services. In today’s ecosystem, a weak link in a vendor’s controls can expose even the most security-conscious firms to breach-level consequences.
Ghost Calls: New Covert Post-Exploitation C2 Method via Zoom and Teams
Security researchers have revealed a novel post-exploitation method dubbed “Ghost Calls,” which abuses WebRTC functionality in conferencing apps like Zoom and Microsoft Teams.
By leveraging TURN servers, a key component used to relay traffic through NAT firewalls, attackers can initiate silent or unanswered calls that are indistinguishable from benign session traffic.
These TURN-based tunnels allow malicious payloads or C2 commands to pass undetected across otherwise legitimate collaboration traffic.
The key advantage for attackers lies in the use of legitimate credentials and encrypted standard protocols. This means conventional detection systems that rely on payload inspection or signature-based alerts are often bypassed entirely.
Because Ghost Calls leave little forensic trace, incident responders face significant challenges when trying to reconstruct timelines or pinpoint ingress vectors.
Unlike zero-day exploits, Ghost Calls exemplify a strategic pivot toward abusing trusted platforms and infrastructure. Organizations must now reevaluate their threat models for conferencing apps, treating them as critical surfaces that require rigorous logging, behavioral analytics, and possibly endpoint inspection to detect post-exploitation persistence.
Security teams should consider isolating conferencing tools from sensitive network segments and continuously monitor for unusual WebRTC or TURN activity patterns indicative of covert abuse.
CVE-2025-53786: Post-Exploitation Privilege Escalation in Exchange Hybrid Environments
Microsoft disclosed CVE-2025-53786 on August 6, 2025, warning of a high-severity vulnerability in hybrid Exchange environments. Both Microsoft and the Cybersecurity and Infrastructure Security Agency (CISA) confirmed the vulnerability in their published guidance.
It affects Exchange Server 2016, 2019, and Subscription Edition and allows privilege escalation from on-prem administrative accounts into Exchange Online through a shared service principal.
The issue is particularly serious due to the difficulty in detecting these escalations and the broad access they can provide across cloud-based assets.
The shared service principal acts as a trust bridge in hybrid environments, enabling seamless identity flow between on-premises and cloud assets. However, this also presents a potential pathway for threat actors who have already compromised local admin credentials.
With that access, attackers can leverage the hybrid trust relationship to assume roles in Exchange Online, often without leaving detectable logs or triggering standard alerts.
This type of post-exploitation activity is especially dangerous because it takes advantage of architectural convenience and visibility gaps in cross-platform environments.
Hybrid Exchange deployments serve as critical yet under-monitored systems in many organizations. The flaw exposed by CVE-2025-53786 starkly reminds security teams to govern and audit federated identities as rigorously as any on-prem authentication mechanism.
Organizations should consider implementing dedicated security policies for hybrid environments, regularly auditing service principals and conditional access configurations, and applying Microsoft’s recommended patches and mitigation strategies without delay.
The Cost of Ignoring Post-Exploitation Techniques
These three incidents collectively underscore a growing trend: attackers aren’t just breaching perimeters—they’re embedding themselves in trusted systems to maximize impact.
Whether through vendor compromise, abuse of communications infrastructure, or identity federation flaws, post-exploitation techniques are becoming a cornerstone of modern attack campaigns.
Security teams must broaden their detection strategies, monitor lateral movement pathways, and treat every layer of access as a potential vector for persistent threat activity.
Explore RSI Security’s Services to Counter Post-Exploitation Threats
RSI Security offers targeted solutions to mitigate post-exploitation risks, including vendor risk assessments, hybrid Exchange security audits, and threat detection services tailored to collaboration tools.
By proactively securing these often-overlooked attack surfaces, organizations can build more resilient defenses against today’s advanced adversaries.
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