Find sigma rule 
Attack: Ingress Tool Transfer
Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer).
On Windows, adversaries may use various utilities to download tools, such as copy, finger, certutil, and PowerShell commands such as IEX(New-Object Net.WebClient).downloadString() and Invoke-WebRequest. On Linux and macOS systems, a variety of utilities also exist, such as curl, scp, sftp, tftp, rsync, finger, and wget.(Citation: t1105_lolbas)
Adversaries may also abuse installers and package managers, such as yum or winget, to download tools to victim hosts. Adversaries have also abused file application features, such as the Windows search-ms protocol handler, to deliver malicious files to victims through remote file searches invoked by User Execution (typically after interacting with Phishing lures).(Citation: T1105: Trellix_search-ms)
Files can also be transferred using various Web Services as well as native or otherwise present tools on the victim system.(Citation: PTSecurity Cobalt Dec 2016) In some cases, adversaries may be able to leverage services that sync between a web-based and an on-premises client, such as Dropbox or OneDrive, to transfer files onto victim systems. For example, by compromising a cloud account and logging into the service’s web portal, an adversary may be able to trigger an automatic syncing process that transfers the file onto the victim’s machine.(Citation: Dropbox Malware Sync)
MITRE
Tactic
- command-and-control
technique
- T1105
Test : certutil download (urlcache)
OS
- windows
Description:
Use certutil -urlcache argument to download a file from the web. Note - /urlcache also works!
Executor
command_prompt
Sigma Rule
- file_event_win_shell_write_susp_directory.yml (id: 1277f594-a7d1-4f28-a2d3-73af5cbeab43)