Adversaries may upload tools to third-party or adversary controlled infrastructure to make it accessible during targeting. Tools can be open or closed source, free or commercial. Tools can be used for malicious purposes by an adversary, but (unlike malware) were not intended to be used for those purposes (ex: [PsExec](https://attack.mitre.org/software/S0029)). Adversaries may upload tools to support their operations, such as making a tool available to a victim network to enable [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105) by placing it on an Internet accessible web server.

Tools may be placed on infrastructure that was previously purchased/rented by the adversary ([Acquire Infrastructure](https://attack.mitre.org/techniques/T1583)) or was otherwise compromised by them ([Compromise Infrastructure](https://attack.mitre.org/techniques/T1584)).(Citation: Dell TG-3390) Tools can also be staged on web services, such as an adversary controlled GitHub repo, or on Platform-as-a-Service offerings that enable users to easily provision applications.(Citation: Dragos Heroku Watering Hole)(Citation: Malwarebytes Heroku Skimmers)(Citation: Intezer App Service Phishing)

Adversaries can avoid the need to upload a tool by having compromised victim machines download the tool directly from a third-party hosting location (ex: a non-adversary controlled GitHub repo), including the original hosting site of the tool.
Upload Tool
source_name: mitre-attack  url: https://attack.mitre.org/techniques/T1608/002  external_id: T1608.002     source_name: Dell TG-3390  description: Dell SecureWorks Counter Threat Unit Threat Intelligence. (2015, August 5). Threat Group-3390 Targets Organizations for Cyberespionage. Retrieved August 18, 2018.  url: https://www.secureworks.com/research/threat-group-3390-targets-organizations-for-cyberespionage     source_name: Malwarebytes Heroku Skimmers  description: Jérôme Segura. (2019, December 4). There's an app for that: web skimmers found on PaaS Heroku. Retrieved August 18, 2022.  url: https://www.malwarebytes.com/blog/news/2019/12/theres-an-app-for-that-web-skimmers-found-on-paas-heroku     source_name: Dragos Heroku Watering Hole  description: Kent Backman. (2021, May 18). When Intrusions Don’t Align: A New Water Watering Hole and Oldsmar. Retrieved August 18, 2022.  url: https://www.dragos.com/blog/industry-news/a-new-water-watering-hole/     source_name: Intezer App Service Phishing  description: Paul Litvak. (2020, October 8). Kud I Enter Your Server? New Vulnerabilities in Microsoft Azure. Retrieved August 18, 2022.  url: https://www.intezer.com/blog/malware-analysis/kud-i-enter-your-server-new-vulnerabilities-in-microsoft-azure/     