T03 · Remote Payload Retrieval and Execution
Error
- Location
SKILL.md:24- Finding
Unverified remote PowerShell installer is executed directly
- Content
View full analysis
Windows 需先确保 `bun` 可用。若不可用：`powershell -c "irm bun.sh/install.ps1 | iex"`，安装后重启终端确认 `bun --version`。 ``` ### Technical Analysis The Skill instructs the Agent to retrieve a mutable PowerShell script from `bun.sh` using `Invoke-RestMethod` and pass the response directly to `Invoke-Expression`. The remote content is not pinned to a version, downloaded for inspection, authenticated with a bundled public key, or checked against an independently trusted digest. Consequently, the reviewed Skill package does not contain the effective payload that will be executed. The behavior exceeds the minimum privilege needed to retrieve news because installing a runtime through an unverified pipe-to-interpreter command gives an external server a general-purpose command-execution channel. ### Attack Path 1. A Windows user invokes the Skill on a system without Bun. 2. The Skill directs the Agent or user to run the documented PowerShell command. 3. PowerShell retrieves the current response from `https://bun.sh/install.ps1`. 4. A compromised server, delivery path, or upstream release infrastructure supplies modified PowerShell. 5. `Invoke-Expression` immediately executes the modified response. 6. The payload runs with all privileges available to the PowerShell process. ### Impact Assessment An attacker controlling the retrieved response could execute arbitrary commands with the current user’s privileges. This could include reading or modifying user-accessible files, accessing credentials available to that user, installing additional software, changing application configuration, or establishing persistence. The command does not itself elevate privileges, but its scope includes everything accessible to the invoking account. ]]>- Remediation
View remediation