GuLoader Obfuscation Analysis | ThreatLabz

Technical analysis of GuLoader’s anti-analysis techniques including polymorphic code and exception-based control flow obfuscation.

2026-02-03 (Tuesday): #GuLoader for #AgentTesla style malware with FTP data exfiltration.

A #pcap of the infection traffic, associated files, and a list of indicators are available at https://www.malware-traffic-analysis.net/2026/02/03/index.html

Two online sandboxes tag this sample as AgentTesla, but I'm not sure what the actual name of this malware is.

- https://tria.ge/260203-tvhlyahx7c
- https://app.any.run/tasks/0840196f-2b8f-415c-8ca7-af0c8f394b0d

Watch out as a new email attack uses fake employee reports to deliver Guloader and Remcos RAT malware, tricking users into running dangerous files disguised as performance reviews.

Read: https://hackread.com/fake-employee-reports-guloader-remcos-rat-malware/

#Malware #Guloader #RemcosRAT #Phishing #CyberSecurity

Fake Employee Reports Spread Guloader and Remcos RAT Malware

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🔍 Fresh, actionable threat intelligence for security leaders.
This report covers three high-impact malware families affecting Windows and mobile environments:
🔹 #Albiriox, an Android banking trojan offered as MaaS, combining VNC-based remote control and overlays to bypass protections in 400+ financial apps.
🔹 #OctoRAT, a .NET-based Windows RAT with UAC bypass, credential theft, proxying, and full remote control for long-term access.
🔹 #GuLoader, a downloader using heavily obfuscated PowerShell, shellcode, and process injection to deliver RATs and infostealers.

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#cybersecurity #infosec

Top 10 last week's threats by uploads 🌐
⬇️ #Xworm 350 (988)
⬇️ #Vidar 184 (278)
⬇️ #Stealc 180 (255)
⬇️ #Asyncrat 176 (319)
⬇️ #Lumma 167 (190)
⬇️ #Quasar 159 (323)
⬇️ #Salatstealer 158 (174)
⬆️ #Mirai 104 (85)
⬇️ #Guloader 73 (153)
⬇️ #Agenttesla 65 (93)
Explore malware in action: https://app.any.run/?utm_source=mastodon&utm_medium=post&utm_campaign=top_ten&utm_term=050126&utm_content=linktoregister#register

#infosec

Top 10 last week's threats by uploads 🌐
⬆️ #Xworm 988 (549)
⬇️ #Quasar 323 (353)
⬆️ #Asyncrat 319 (244)
⬇️ #Vidar 278 (282)
⬆️ #Stealc 255 (220)
⬇️ #Lumma 190 (221)
⬆️ #Gravityrat 188 (46)
⬆️ #Salatstealer 174 (95)
⬇️ #Guloader 153 (197)
⬇️ #Smoke 138 (148)
Explore malware in action: https://app.any.run/?utm_source=mastodon&utm_medium=post&utm_campaign=top_ten&utm_term=291225&utm_content=linktoregister#register

#cybersecurity #infosec

Top 10 last week's threats by uploads 🌐
⬇️ #Xworm 550 (944)
⬇️ #Quasar 354 (364)
⬇️ #Vidar 282 (371)
⬇️ #Asyncrat 247 (396)
⬇️ #Lumma 222 (284)
⬇️ #Stealc 221 (354)
⬆️ #Guloader 197 (181)
⬆️ #Agenttesla 186 (172)
⬇️ #Smoke 148 (153)
⬇️ #Remcos 128 (212)
Explore malware in action: https://app.any.run/?utm_source=mastodon&utm_medium=post&utm_campaign=top_ten&utm_term=221225&utm_content=linktoregister#register

#cybersecurity #infosec

Top 10 last week's threats by uploads 🌐
⬆️ #Xworm 944 (870)
⬇️ #Asyncrat 396 (413)
⬆️ #Vidar 371 (318)
⬇️ #Quasar 364 (395)
⬆️ #Stealc 354 (266)
⬆️ #Lumma 284 (282)
⬇️ #Remcos 213 (269)
⬆️ #Guloader 181 (179)
⬆️ #Agenttesla 173 (141)
⬇️ #Smoke 153 (158)
Explore malware in action: https://app.any.run/?utm_source=mastodon&utm_medium=post&utm_campaign=top_ten&utm_term=151225&utm_content=linktoregister#register

#cybersecurity #infosec

Les attaquants privilégient l'accès RDP et des outils standards, avec usages ponctuels de GuLoader

Selon Acronis, des tendances récentes montrent une préférence des attaquants pour des approches simples et peu coûteuses, avec un accès initial via RDP et l’usage d’outillage prêt à l’emploi pour progresser dans les réseaux compromis. L’analyse souligne que la plupart des victimes sont compromises par RDP. Après l’accès initial, les acteurs utilisent des outils standards pour la découverte et le mouvement latéral, ainsi que des exploits d’escalade de privilèges (LPE), des AV killers (notamment via des drivers vulnérables), des terminateurs de processus, des désinstalleurs ciblés et des outils d’accès aux identifiants comme Mimikatz.

CyberVeille

Top 10 last week's threats by uploads 🌐
⬆️ #Xworm 870 (854)
⬆️ #Asyncrat 415 (398)
⬆️ #Quasar 395 (329)
⬇️ #Vidar 318 (327)
⬇️ #Lumma 286 (322)
⬆️ #Remcos 273 (212)
⬇️ #Stealc 266 (296)
⬇️ #Gravityrat 241 (302)
⬆️ #Guloader 179 (172)
⬆️ #Smokeloader 155 (144)

Explore malware in action: https://app.any.run/?utm_source=mastodon&utm_medium=post&utm_campaign=top_ten&utm_term=081225&utm_content=linktoregister#register

#cybersecurity #Infosec