fechar
fechar
Sua Rede do Amanhã
Sua Rede do Amanhã
Planeje seu caminho rumo a uma rede mais rápida, segura e resiliente projetada para os aplicativos e usuários aos quais você oferece suporte.
          Experimente a Netskope
          Coloque a mão na massa com a plataforma Netskope
          Esta é a sua chance de experimentar a plataforma de nuvem única do Netskope One em primeira mão. Inscreva-se em laboratórios práticos e individualizados, junte-se a nós para demonstrações mensais de produtos ao vivo, faça um test drive gratuito do Netskope Private Access ou participe de workshops ao vivo conduzidos por instrutores.
            Líder em SSE. Agora é líder em SASE de fornecedor único.
            Líder em SSE. Agora é líder em SASE de fornecedor único.
            A Netskope estreia como líder no Quadrante Mágico™ do Gartner® para Single-Vendor SASE
              Protegendo a IA generativa para leigos
              Protegendo a IA generativa para leigos
              Saiba como sua organização pode equilibrar o potencial inovador da IA generativa com práticas robustas de segurança de dados.
                E-book moderno sobre prevenção de perda de dados (DLP) para leigos
                Prevenção Contra Perda de Dados (DLP) Moderna para Leigos
                Obtenha dicas e truques para fazer a transição para um DLP fornecido na nuvem.
                  Livro SD-WAN moderno para SASE Dummies
                  SD-WAN moderno para leigos em SASE
                  Pare de brincar com sua arquitetura de rede
                    Compreendendo onde estão os riscos
                    O Advanced Analytics transforma a maneira como as equipes de operações de segurança aplicam insights orientados por dados para implementar políticas melhores. Com o Advanced Analytics, o senhor pode identificar tendências, concentrar-se em áreas de preocupação e usar os dados para tomar medidas.
                        Os 6 casos de uso mais atraentes para substituição completa de VPN herdada
                        Os 6 casos de uso mais atraentes para substituição completa de VPN herdada
                        O Netskope One Private Access é a única solução que permite que o senhor aposente sua VPN definitivamente.
                          A Colgate-Palmolive protege sua “propriedade intelectual "” com proteção de dados inteligente e adaptável
                          A Colgate-Palmolive protege sua “propriedade intelectual "” com proteção de dados inteligente e adaptável
                            Netskope GovCloud
                            Netskope obtém alta autorização do FedRAMP
                            Escolha o Netskope GovCloud para acelerar a transformação de sua agência.
                              Vamos fazer grandes coisas juntos
                              A estratégia de comercialização da Netskope, focada em Parcerias, permite que nossos Parceiros maximizem seu crescimento e lucratividade enquanto transformam a segurança corporativa.
                                Netskope solutions
                                Netskope Cloud Exchange
                                O Netskope Cloud Exchange (CE) oferece aos clientes ferramentas de integração poderosas para alavancar os investimentos em toda a postura de segurança.
                                  Suporte Técnico Netskope
                                  Suporte Técnico Netskope
                                  Nossos engenheiros de suporte qualificados estão localizados em todo o mundo e têm diversas experiências em segurança de nuvem, rede, virtualização, fornecimento de conteúdo e desenvolvimento de software, garantindo assistência técnica de qualidade e em tempo hábil.
                                    Vídeo da Netskope
                                    Treinamento Netskope
                                    Os treinamentos da Netskope vão ajudar você a ser um especialista em segurança na nuvem. Conte conosco para ajudá-lo a proteger a sua jornada de transformação digital e aproveitar ao máximo as suas aplicações na nuvem, na web e privadas.

                                      Leaky Helpdesk – Accidental Exposure of Zendesk Attachments

                                      Jul 22 2020

                                      Does your helpdesk publicly expose the files you upload to it? Is there malware lurking in your helpdesk? In this latest edition of our leaky cloud app series, we uncover publicly accessible data in the Zendesk instances belonging to more than 350 organizations. This exposed data includes confidential information, malware, and even some COVID-19 themed Trojans. This blog post quantifies the scope of the problem and identifies steps you can take to lock down your Zendesk instance and prevent unwanted exposure. 

                                      This is the fourth installation of our leaky cloud app series, in which we highlight the many different ways cloud data leaks occur and provide guidance to avoid them. Our earlier posts covered Google Calendar, Google Groups, and Google Link Sharing

                                      Zendesk attachments

                                      By default, Zendesk attachments are accessible to anyone who has the link requiring no authentication. This is the root cause of the exposures we have discovered.

                                      Zendesk attachment links are in the format – http://<instance>.zendesk.com/attachments/token/<token_id>/?name<file_name>

                                      • instance – Name of the instance
                                      • token_id – Token for the attachment (generally with the length of 25 characters (a-z0-9))
                                      • file_name – Name of the file

                                      The shared attachment links by default can be accessed by anyone who has the link without any authentication. Though this won’t make the data indexable by search engines, it can likely pose exposure concerns in the following ways:

                                      • If a link is leaked, it can be accessed by anyone regardless of whether they are part of your organization.
                                      • Users can access the links even after leaving the organization.

                                      Among the different types of data we discovered via leaked links from more than 350 organization were: 

                                      • Employee resumes
                                      • Travel itineraries and documents
                                      • Bank and financial statements
                                      • Product installation guides
                                      • Emails
                                      • Invoices and purchase orders
                                      • Customer contact details
                                      • Medical documents
                                      • Social security numbers, driver’s license numbers, and bank account numbers
                                      • Product features and roadmaps
                                      • Passwords
                                      • Logfiles and screenshots
                                      • License keys
                                      • Meeting links
                                      • Drivers licenses and passports

                                      The instances that exposed the data belonged to private, public, and government organizations working in the following industries:

                                      • Retail and e-commerce
                                      • Hospitals and medical firms
                                      • Travel agencies
                                      • Educational institutions
                                      • Consultancies

                                      Zendesk spreading malware

                                      Any cloud service that provides file hosting via public, unauthenticated links can potentially be used to spread malware. In this section, we describe one such instance we uncovered of publicly accessible malware hosted in Zendesk. We have previously blogged about other apps being used as an attack vector in the same way, including a Salesforce Pardot CRM attack.

                                      Support portals typically have lots of people outside the organization creating tickets and uploading attachments. This increases the possibility of a compromised device, compromised account, or malicious user attaching malware to a ticket.

                                      This is problematic in two regards. First, the tickets and attachments are likely to be widely shared within the target organization, and therefore can also be used to spread malware within the organization. Second, if the attachments are public, the link to the malware can be used to target victims anywhere on the Internet. Hosting malware in cloud applications is a common tactic used to avoid detection by products that rely solely on URL reputation. 

                                      Malicious Excel spreadsheet 

                                      One of the publicly shared malware threats we found in Zendesk belonged to a large retailer in the United States and contained a COVID-19 lure: a malicious Excel file named  covid19_<masked>.xls.  The threat actor embedded a malicious Excel 4 macro formula in one of the 16 hidden sheets. Excel macros were used instead of the VBA macros commonly used in malicious Excel files, as they are both less likely to be detected by scanning engines and more likely to be enabled in the editor.

                                      The Excel 4 macro formulas are invoked in the workbook by using the “Auto_Open” option to download the next stage payload from toliku[.]com. At the time of analysis, the URL was down and not serving any payload, but was previously serving the Dridex malware.

                                      Figure 1 shows how to view the sheet ‘QMBVLCQaJJviKgsHo’ which contains the malicious URL.

                                      Figure showing URL hidden as an Excel 4 macros formula in a hidden sheet.
                                      Figure 1: URL hidden as an Excel 4 macros formula in a hidden sheet

                                      Disclosure

                                      Netskope reported the exposures we uncovered to the affected organizations in July 2020.

                                      Conclusion

                                      This edition of our leaky cloud apps series provided a detailed synopsis of how confidential information gets leaked through misconfigured Zendesk attachment links. We also detailed how malware can spread using Zendesk. We recommend turning on the “Require authentication to download” option to avoid accidental exposure as shown in Figure 2.

                                      Figure 2: Default option for attachments in Zendesk

                                      After enabling this option, private linked attachments with the shared file links will now require authentication.

                                      author image
                                      Ashwin Vamshi
                                      Ashwin Vamshi is a Security Researcher with innate interest in targeted attacks and malwares using cloud services.
                                      Ashwin Vamshi is a Security Researcher with innate interest in targeted attacks and malwares using cloud services.

                                      Mantenha-se informado!

                                      Assine para receber as últimas novidades do Blog da Netskope