Vitalii K.
Private message 
Offer work 
Lvov,
Ukraine
1 year back
available for hire
on the service 2 years
Rating
Successful projects
Average rating
Language proficiency level
Українська: fluent
Skills and abilities
Programming
Portfolio
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56 USD Deploy a mail server and add security DNS records
System & Network Administration
Task: The client requested to set up a mail server for their business, ensure the proper functioning of sending and receiving emails, and configure all necessary security records (SPF, DKIM, DMARC) to avoid emails landing in spam.
The work included:
— Deploying a mail server on a dedicated VPS.
… — Setting up secure authentication and encryption using SSL/TLS.
— Configuring DNS records (SPF, DKIM, DMARC) to protect the domain from spoofing and enhance the reliability of sent emails.
— Conducting testing for compliance with mail service standards and checking that emails do not land in spam.
— Optimizing server settings for stable and reliable operation.
— Testing the server on the Mail-tester.com platform to achieve the highest rating in terms of mail settings and security.
Results:
— Successfully configured mail server that meets modern security standards.
— All client emails are reliably sent and delivered to recipients' inboxes without landing in spam.
— High level of protection against fraud and fake emails ensured through the implementation of SPF, DKIM, and DMARC.
— Improved domain reputation, contributing to the seamless operation of the mail system.
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226 USD External audit of web application security
Cybersecurity & Data Protection
Task: Conducting an external security audit of the web application [NDA] to identify potential vulnerabilities, assess the level of protection, and ensure compliance with best practices in cybersecurity. The main goal was to identify potential threats and provide recommendations for their mitigation, thereby increasing the overall security level of the web application.
The work included:
… — Initial review: Gathering information about the web application, including its structure, technologies used, and external integrations, to understand the overall security context.
— Automated IAST/DAST scanning: Performing dynamic and interactive security analysis of the application using automated tools to detect vulnerabilities at the code level and during application execution.
— Semi-automated/manual scanning: Conducting detailed semi-automated and manual checks to identify complex vulnerabilities that may be missed by automated tools.
— Host harvesting: Identifying domains, subdomains, and IP addresses associated with the web application (Host Harvesting / Subdomain Discovery) for further security analysis.
— Host and IP address analysis (WEBINT): Conducting reconnaissance (WEBINT) to gather information about hosts and IP addresses, allowing the identification of potential entry points for attacks.
— Network perimeter overview: Assessing the security of the web application's network perimeter, identifying open ports and services, and evaluating risks.
— DNS zone analysis (DNS Discovery): Checking DNS zone configurations for possible vulnerabilities and misconfigurations.
— TLS/SSL analysis: Verifying TLS/SSL settings to ensure robust data encryption and protection against known protocol-level attacks.
— SMTP server analysis: Assessing the security of the SMTP server, including authentication settings and spam protection.
— FTP server analysis: Checking the FTP server for vulnerabilities such as unprotected data transmission or weak passwords.
— SQL server analysis: Checking the SQL server for vulnerabilities such as SQL injection or misconfigured security settings.
— SSH server analysis: Assessing the security of the SSH server, including authentication settings, brute force protection, and the use of strong keys.
— HTTP header analysis: Checking the configuration of HTTP headers to prevent XSS, Clickjacking, injections, and other types of threats.
— Technology lookup: Identifying technologies and frameworks used on the site to detect possible vulnerabilities in their configuration.
— Structure parsing (file and URL collection): Collecting and analyzing all available files and URLs on the site for further vulnerability testing.
— URL parameter analysis: Checking URL parameters for possible vulnerabilities such as SQL injection or XSS.
— Source code analysis: Conducting source code analysis to identify logical errors, code vulnerabilities, and other risks.
— Web element analysis: Detailed testing of POST/GET requests, forms, and other web elements for vulnerabilities.
— Vulnerability identification and assessment: Collecting and assessing all identified vulnerabilities, including classifying them by severity level.
— Report preparation: Compiling a detailed report that includes all identified vulnerabilities, their potential impact on the web application's security, and recommendations for risk mitigation.
Result: The web application underwent a comprehensive security analysis, allowing for the identification and remediation of critical vulnerabilities. After implementing the recommended security measures, a high level of application protection was ensured, significantly reducing the risk of successful attacks and providing a secure environment for users.
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135 USD Detection and removal of malicious code on the website
Cybersecurity & Data Protection
Task: The client reported an issue with suspicious behavior on the website [NDA], indicating a possible malware infection. The goal was to detect and remove the malicious code to restore the safe operation of the site and prevent further spread of threats.
The work included:
… — Initial audit: Conducting a scan of the site to detect malicious code, hidden scripts, and other suspicious elements.
— Detection of malicious code: Malicious code was found in the file:
/home/[nda]/[nda]/www/catalog/view/javascript/jquery/jquery-2.1.1.min.js
— Reverse analysis of the malicious code: The malicious code document.write(""+"") implemented an encrypted redirect to CDN34.com, which redirected users to malicious sites.
— Analysis and removal: The malicious code was removed from the relevant file, after which a complete review of other files was conducted to ensure the absence of similar threats on the site.
— File restoration: The original, clean file jquery-2.1.1.min.js was restored to ensure its proper functioning without malicious elements.
— Site check after removal: After the malicious code was removed, the site was tested for security and proper operation to ensure the absence of further threats.
Result: The malicious code was successfully detected and removed from the site. The safe operation of the web resource was restored, the redirect to malicious sites was stopped, protecting users from potential threats. Recommendations for further security measures were prepared to prevent reinfection.
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113 USD Cleaning the website from viruses
Cybersecurity & Data Protection
Task: The client reported an issue with the website [NDA] being infected with malware, which led to dangerous behavior of the resource and potential compromise of user data. The goal was to completely clean the site of viruses, restore its security, and protect against similar threats in the future.
The work included:
… — Initial audit: Conducting a comprehensive scan of the site to detect malicious code, hidden scripts, and harmful files using specialized tools and analysis methods.
— Identification of the source of infection: Determining the pathways through which the malware entered the site, such as vulnerabilities in the CMS, plugins, or uploaded files.
— Removal of malicious code: Complete cleaning of files and databases from malicious code, scripts, and backdoors. Deleting or replacing infected files with clean copies.
— Audit and strengthening of configurations: Checking and updating all configuration files, databases, as well as access rights to minimize the risks of reinfection.
— Installation and configuration of security measures: Installing and configuring protective tools such as a Web Application Firewall (WAF), antivirus scanner on the server, and monitoring tools to detect and block threats in real-time.
— Rescanning and testing: Conducting a rescan of the site after cleaning to confirm the absence of viruses and other malicious elements.
— Providing security recommendations: Developing recommendations for the client on maintaining the security of the site, including regular updates, backups, and monitoring.
Result: The site was completely cleaned of malware, and its secure operation was restored. After the work was completed, all test checks showed no threats. Additional security measures were implemented to help protect the site from similar attacks in the future.
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90 USD Improvement of SSL/TLS security for web application
Cybersecurity & Data Protection
Task: The task involved enhancing the SSL/TLS configuration security level of the web application [NDA] to ensure reliable data encryption transmitted between the server and clients. The goal is to protect against Man-in-the-Middle attacks, weak cipher abuses, and other threats related to improper SSL/TLS configuration.
The work included:
… — Audit of the current SSL/TLS configuration: Checking the protocols, ciphers, and settings used for compliance with best security practices.
— Disabling insecure protocols: Turning off outdated and vulnerable protocols such as SSL 2.0 and TLS 1.0/1.1 to prevent POODLE attacks and other vulnerabilities.
— Configuring strong ciphers: Ensuring the use of only reliable ciphers for encrypting transmitted data.
— Implementing HSTS (Strict-Transport-Security): Setting up HSTS to enforce HTTPS on all connections, protecting against downgrade attacks.
— Audit and configuration of certificates: Verifying the correctness of SSL certificate installation, their compliance with domains and validity periods, as well as configuring certificates using modern signing algorithms (e.g., SHA-256).
— Testing for SSL/TLS protocol vulnerabilities: Conducting vulnerability tests on SSL/TLS using tools such as SSL Labs and ssltest.sh to check for known threats.
— Optimizing configuration settings: Making changes to achieve a balance between security and performance, including configuring optimal session key and session parameters.
Result: As a result of the work done, the web application received a significantly improved SSL/TLS configuration that provided a high level of protection against transport protocol level attacks. All test checks were successful, confirming compliance with industry best security practices.
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45 USD Add security HTTP headers for the domain
Cybersecurity & Data Protection
Task: I was assigned to enhance the security level of the web application [NDA] by adding and configuring security HTTP headers. The goal was to protect against a wide range of web threats, such as XSS attacks, Clickjacking, MITM, SQL injections, and other vulnerabilities.
The work included:
… — Analyzing the current security state of the web application in terms of missing or misconfigured HTTP headers.
— Adding and configuring critical security headers, such as:
—— Content-Security-Policy (CSP): Preventing the execution of malicious scripts and protecting against XSS attacks.
—— Strict-Transport-Security (HSTS): Enforcing the use of HTTPS for all connections, protecting against data interception attacks.
—— X-Frame-Options: Preventing Clickjacking attacks by restricting the ability to embed pages on third-party sites.
—— X-Content-Type-Options: Protecting against MIME type attacks by disabling automatic content type detection.
—— Referrer-Policy: Controlling what information is passed in the Referrer header.
—— Permissions-Policy: Restricting access to browser APIs that could be used for malicious actions.
— Verifying and testing the changes made to ensure compatibility and effectiveness of the added headers.
— Optimizing header settings for maximum security level without negatively impacting the site's performance and functionality.
— Rescanning and retesting the domain to confirm the correctness and effectiveness of the settings.
Result: After implementing the security HTTP headers, the domain became significantly more protected against a wide range of web attacks. Test results showed a reduction in risks and compliance with best security practices for web applications.
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135 USD Integrate the cybersecurity system and enhance the security of the website.
Cybersecurity & Data Protection
Task: I was assigned to improve the security system of the website [NDA] and protect it from vulnerabilities identified during scanning with Acunetix. The goal was to enhance the site's security level and ensure successful completion of all vulnerability checks.
The work included:
… — Analyzing the Acunetix report and identifying vulnerabilities.
— Auditing the network perimeter to detect weaknesses and potential attack entry points.
— Installing a firewall on the server to protect against unauthorized access and attacks.
— Deploying an external WAF (Web Application Firewall) for additional protection against web attacks.
— Auditing all configuration files with settings for maximum security to minimize potential risks.
— Implementing necessary security measures to eliminate vulnerabilities such as: XSS, SQL injections, SSRF, LFI/RFI, RCE, weak SSL/TLS configurations, and others.
— Optimizing server and web application settings to enhance their resilience to attacks.
— Rescanning the site with Acunetix to confirm the successful elimination of all identified vulnerabilities.
Result: After the work was completed, the site successfully passed the Acunetix scan, confirming its protection against known types of attacks. A high level of security was achieved, reducing the risks of data compromise and improving the overall security posture of the site.
Activity
| Latest proposals 2 | Budget | Added | Deadlines | Proposal | |
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It is necessary to develop a camera spoofer for Android/iPhone.
609 USD
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Need a specialist in pentesting, network security, and data
226 USD
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