☑️Windows File Transfer
Windows comes pre-built with lots of file transfer tools. The blog post from microsoft Microsoft Astaroth Attack talks about fileless threat. The term fileless suggests that a threat doesn't come in a file, they use legitimate tools built into a system to execute an attack. This doesn't mean that there's not a file transfer operation. As discussed later in this section, the file is not "present" on the system but runs in memory.
The Astaroth attack generally followed these steps: A malicious link in a spear-phishing email led to an LNK file. When double-clicked, the LNK file caused the execution of the WMIC tool with the "/Format" parameter, which allowed the download and execution of malicious JavaScript code. The JavaScript code, in turn, downloads payloads by abusing the Bitsadmin tool.
All the payloads were base64-encoded and decoded using the Certutil tool resulting in a few DLL files. The regsvr32 tool was then used to load one of the decoded DLLs, which decrypted and loaded other files until the final payload, Astaroth, was injected into the Userinit process. Below is a graphical depiction of the attack.
This is an excellent example of multiple methods for file transfer and the threat actor using those methods to bypass defenses.
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