# STAC5143: threat group profile

> STAC5143 is a threat group. Public reporting about it is still limited. This free profile brings together what is known about it, so you can judge the risk to you. It lists the other names the group goes by and links to every public report behind it.

Canonical page: https://www.edgeprotect.io/threat-actors/stac5143
Breadcrumb: [Home](https://www.edgeprotect.io/) > [Threat groups](https://www.edgeprotect.io/threat-actors) > STAC5143

## At a glance

| Fact | Value |
|---|---|
| Attack techniques | 0 |
| Thought to operate from | Not known |
| Other names | 0 |
| Public reports | 1 |

## Who is STAC5143?

STAC5143 is a threat group. Public reporting about it is still limited.

### What public reporting says

> STAC5143 is a threat actor group tracked by Sophos, notable for its sophisticated use of Microsoft Office 365's legitimate services to conduct ransomware and data extortion campaigns. Unlike FIN7, which typically targets larger organizations through phishing and malicious Google Ads, STAC5143 focuses on smaller victims across diverse business sectors. Their operations begin with overwhelming targeted individuals with email bombing, followed by Microsoft Teams messages impersonating tech support to initiate a remote screen control session. Utilizing Microsoft's Quick Assist or direct Teams screen sharing, they deploy malware, including Java Archive (JAR) files and Python-based backdoors, from external SharePoint file stores. This cluster exploits legitimate services within the Microsoft Office 365 platform, using a Java-based proxy to execute PowerShell commands and download malicious payloads. While employing publicly available tools like RPivot, their obfuscation methods and the use of side-loaded DLLs for command and control, combined with the deployment of Black Basta ransomware in one instance, indicate a sophisticated and evolving threat actor adapting known techniques for their specific objectives.

## Public reports about STAC5143

- https://news.sophos.com/en-us/2025/01/21/sophos-mdr-tracks-two-ransomware-campaigns-using-email-bombing-microsoft-teams-vishing/

## Frequently asked questions

### Who is STAC5143?

STAC5143 is a threat group. Public reporting about it is still limited.

### How do I know if STAC5143 is a risk to my business?

Create an account and tell us the software you run. We match it against known flaws, including those linked to threat groups, rank each one from 0 to 100 and tell you as soon as we spot something that affects you.

## Check whether it matters to your business

A free EdgeProtect account (no card needed) matches the software you run against known flaws, including those linked to threat groups, ranks each one from 0 to 100 and tells you as soon as we spot something that affects you. It also shows which threat groups and ransomware gangs are hitting your sector, with profiles of over 900 groups and a PDF dossier for each.

- Start free: https://www.edgeprotect.io/register
- Book a demo: https://www.edgeprotect.io/contact