Lost in relocation: analysis of a new loader distributing CASTLESTEALER
A previously undocumented Windows loader tracked as OXLOADER is delivering the CASTLESTEALER infostealer via malicious Google Ads, with low detection rates across static engines and sandbox detonations. The loader uses several obfuscation layers (control-flow flattening, opaque predicates, mixed Boolean-Arithmetic), self-modifying decryption stubs, and abuses the Windows .reloc section to stage shellcode. Elastic Security Labs identified OXLOADER in an active campaign targeting one of our…