Security Affairs covered new research on April 23 documenting a Linux port of the GoGra backdoor, originally seen as Windows-only. The Linux variant retains GoGra's defining feature: it uses Microsoft Graph API as its command-and-control channel, fetching commands from Outlook drafts in an attacker-controlled Microsoft 365 tenant and writing results back to the same drafts. Because the C2 traffic is HTTPS to graph.microsoft.com - the same endpoint legitimate clients hit constantly - it is invisible to most network-layer detections. The Linux port targets enterprise Linux servers with Outbound 443 access to Microsoft cloud services, broadening reach onto build servers and jump hosts.
ESET disclosed GopherWhisper, a previously undocumented China-linked spy group active since at least November 2023 and targeting Mongolian government systems. The group's defining trick: instead of building its own command-and-control servers, it sends instructions through ordinary cloud services - private Slack channels, Discord servers, Outlook draft email folders, and the file.io file-sharing service. Because the malware traffic looks like normal Slack and Discord usage, network monitoring tools largely ignore it. ESET extracted thousands of operator messages from the attackers' own Slack and Discord workspaces, and even found a 'How to write RATs.txt' file in their Downloads folder.
TrustStrike Labs