Hire the Best Antispam and Antivirus Specialists
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Infrastructure & Security Specialist specializing in Linux, VMware, Hyper-V, Windows Server, Oracle databases, infrastructure troubleshooting, security incident response, virtualization, and production systems support. I help businesses investigate security incidents, recover compromised Linux and WordPress environments, harden infrastructure, stabilize production systems, and resolve complex hosting, virtualization, and server issues. My experience includes: ✔ Security incident response & malware remediation ✔ WordPress malware removal & website recovery ✔ Server hardening & security auditing ✔ SSH, access control & authentication hardening ✔ VMware & Hyper-V virtualization ✔ Windows Server administration ✔ Linux systems administration ✔ Oracle Database administration & troubleshooting ✔ Infrastructure troubleshooting & performance analysis ✔ RAID, storage & recovery diagnostics ✔ VPS, dedicated server & hosting environments ✔ Backup & disaster recovery support ✔ PowerShell & Bash automation ✔ Email, DNS & server migrations ✔ Monitoring, stability & capacity planning Recent projects include security incident response and malware remediation across 155+ WordPress websites, Hyper-V VM scaling and performance stabilization, RAID recovery diagnostics on HPE servers, Linux/WHMCS migrations, Oracle environment troubleshooting, mail infrastructure troubleshooting, and production environment recovery. I focus on identifying root causes quickly, minimizing downtime, and delivering practical, production-ready solutions for critical systems and business infrastructure.

Configure, monitor, and maintain routers and switches (access, aggregation, and service routers). Implement and troubleshoot dynamic routing protocols (BGP, IS-IS, OSPF) and static routing. Manage QoS policies including policing, shaping, and traffic prioritization. Analyze and resolve issues related to L2VPN, L2TP, NAT, TCP/UDP performance, and network slicing. Work with synchronization technologies such as PTP and SyncE, including troubleshooting PDV, servo states, and ESMC/SSM propagation. Support optical and transport technologies (DWDM, OTU4, OSC, SDH/SONET). Conduct network performance testing, monitoring (alarms, PDV measurements, interface utilization), and packet analysis (e.g., Wireshark). Provide expertise in access vs. service router roles and integration with SIP/SBC infrastructure. Document network designs, configurations, and troubleshooting procedures.

Network & IT Infrastructure Expert | Mikrotik | VPN | Linux | Cloud With 25 years of experience in IT infrastructure and network engineering, I specialize in designing, securing, and optimizing network systems for businesses of all sizes. Whether you need a reliable VPN solution, a secure network setup, or an optimized server infrastructure, I can help you achieve your goals efficiently. What I Offer: Mikrotik & Network Configuration – Routing, Firewall, VLANs, QoS, Wireless VPN & Secure Networking – WireGuard, OpenVPN, IPsec, GRE tunnels Linux System Administration – Ubuntu, CentOS, Debian, server automation Cloud & Backup Solutions – Veeam, Rsync, ZFS, Proxmox, Disaster Recovery Server & API Hosting – OpenStreetMap servers, self-hosted solutions Troubleshooting & Performance Optimization – Network monitoring, security hardening Web Development – Next.js websites, WordPress to Next.js migrations I have worked with businesses, startups, and enterprise clients to ensure their IT infrastructure is secure, scalable, and high-performing. My approach is straightforward – I analyze, optimize, and deliver solutions that just work. Let’s connect and discuss how I can help with your project!

Hello, My name is Djordje. Im experienced NOC engineer. From 2009 I’m working in sphere of internet technologies. My first job was technical support at YUBC net ISP company. Also I worked for Orion ISP company as NOC engineer, after Orion i was also worked as NOC engineer at Telenor mobile company. Now i work at Telesign company also as NOC engineer. I like to learn new stuff, and my interests are networking. I m also at basic level of Linux admistration knowledge. Since 2021. I started Cyber Security path in my career, so I first work as Information Security Analyst for 2 years, gain ComTia Security + Certificate and moved forward as Security Engeener. I have lot of expirience with cyber security procedures, can help with gaining Cyber Essentials and Cyber Essentials Plus certificates

🔬 Reverse Engineering & Security Analysis Binary analysis for security vulnerabilities, legacy system documentation, and interoperability Software activation integrity assessment to help vendors protect their IP Firmware unpacking, bootloader analysis, and embedded system forensics APK decompilation for security auditing and compliance 🛡️ Anti-Cheat Consulting & Game Integrity Reverse engineering of cheating tools to help game studios improve detection Design and audit of kernel-level anti-cheat systems (Windows, Linux) Memory integrity verification, handle stripping, and hypervisor-assisted detection Threat intelligence on cheat marketplaces and subscription models to strengthen product defense ☣️ Malware, Rootkit & Threat Analysis Full dissection of ransomware, backdoors, infostealers, and banking trojans Kernel-mode rootkit and bootkit forensics (DKOM, SSDT hooks, IRP filtering) Threat intelligence reporting with custom Yara rule creation Incident response support: rootkit and ransomware removal from servers and workstations 🔐 VPN & Network Security VPN setup, troubleshooting, and hardening (WireGuard, OpenVPN, IPsec) Traffic analysis, firewall configuration, and network segmentation Deep packet inspection (DPI) and protocol analysis for anomaly detection Secure infrastructure design for high-risk environments (journalists, activists, enterprises)

✅ Professional Penetration Tester ✅ 3500+ Hours ✅ Top Rated Plus Freelancer Security Researcher and Penetration Tester recognized by the U.S. Department of Defense, AT&T, Sony, and Semrush for the responsible disclosure of 40+ vulnerabilities via HackerOne. Since 2022, an active member of the Synack Red Team - an elite tier of offensive security specialists vetted through rigorous technical and background screening. Every engagement concludes with a comprehensive technical report built to satisfy the specific penetration testing controls required for HIPAA, ISO 27001, SOC2, and PCI-DSS. I provide a high-level executive summary for stakeholders alongside deep-dive technical findings, fully reproducible Proofs-of-Concept (PoC), and prioritized remediation steps to ensure your team can effectively close every gap before your audit. Specializing in black and gray box testing of live web applications, cloud environments, and networks, covering all common attack vectors, business logic flaws, and discovering previously undisclosed vulnerabilities (0days) to prevent high-impact data breaches. Service Description: 1) Web Application Penetration Testing (OWASP Top 10, PTES, ASVS, Business Logic Testing) 2) Mobile Application Penetration Testing (OWASP Top 10, MASVS, MASTG, PTES) 3) Network Penetration Testing (Active Directory, Entra ID, Internal & External Network) 4) API Security Testing - REST, GraphQL, SOAP, gRPC, Webhooks (OWASP API Top 10) 5) Cloud Security Testing - AWS/Azure/GCP/OCI/Alibaba/IBM/DigitalOcean/SaaS/IaaS/PaaS 6) Cloud-Native & Container Security (Kubernetes, Docker, OpenShift, EKS/AKS/GKE) 7) LLM Security Testing (OWASP LLM Top 10, Prompt Injection, Data Poisoning) Tools used in engagements: BurpSuite Professional | Custom Python scripts | BloodHound | Impacket Framework | Responder | Metasploit | Mimikatz | Nuclei | Nmap | FRIDA | Android Studio | Postman Identify and secure your attack surface before threat actors do ! Message me to discuss your project requirements.