Query: threat report mentioning Build Image on Host
Matching passage: T1612 Build Image on Host. Tactics: stealth. Description: Adversaries may build a container image directly on a host to bypass defenses that monitor for the retrieval of malicious images from a public registry. A remote <code>build</code> request may be sent to the Docker API that includes a Dockerfile that pulls a vanilla base image, such as alpine, from a public or local registry and then builds a custom image upon it.(Citation: Docker Build Image) An adversary may take advantage of that <code>build</code> API to build a custom image on the host that includes malware downloaded from their C2 server, and then they may utilize [Deploy Container](https://attack.mitre.org/techniques/T1610) using that custom image.(Citation: Aqua Build Images on Hosts)(Citation: Aqua Security Cloud Native Threat Report June 2021) If the base image is pulled from a public registry, defenses will likely not detect the image as malicious since it’s a vanilla image. If the base image already resides in a local registry, the pull may be considered even less suspicious since the image is already in the environment.
Near-miss passage: T1564.006 Run Virtual Instance. Tactics: stealth. Description: Adversaries may carry out malicious operations using a virtual instance to avoid detection. A wide variety of virtualization technologies exist that allow for the emulation of a computer or computing environment. By running malicious code inside of a virtual instance, adversaries can hide artifacts associated with their behavior from security tools that are unable to monitor activity inside the virtual instance.(Citation: CyberCX Akira Ransomware) Additionally, depending on the virtual networking implementation (ex: bridged adapter), network traffic generated by the virtual instance can be difficult to trace back to the compromised host as the IP address and hostname might not match known values.(Citation: SingHealth Breach Jan 2019) Adversaries may utilize native support for virtualization (ex: Hyper-V), deploy lightweight emulators (ex: QEMU), or drop the necessary files to run a virtual instance (ex: VirtualBox binaries).(Citation: Securonix CronTrap 2024) After running a virtual instance, adversaries may create a shared folder between the guest and host with permissions that enable the virtual instance to interact with the host file system.(Citation: Sophos Ragnar May 2020) Threat actors may also leverage temporary virtualized environments such as the Windows Sandbox, which supports the use of `.wsb` configuration files for defining execution parameters. For example, the `<MappedFolder>` property supports the creation of a shared folder, while the `<LogonCommand>` property allows the specification of a payload.(Citation: ESET MirrorFace 2025)(Citation: ITOCHU Hack the Sandbox)(Citation: ITOCHU Sandbox PPT) In VMWare environments, adversaries may leverage the vCenter console to create new virtual machines. However, they may also create virtual machines directly on ESXi servers by running a valid `.vmx` file with the `/bin/vmx` utility. Adding this command to `/etc/rc.local.d/local.sh` (i.e., [RC Scripts](https://attack.mitre.org/techniques/T1037/004)) will cause