China-Aligned Bronze Sandcastle Abuses Sandboxie DLL Sideloading to Deploy Backdoors

Cybersecurity researchers have disclosed details of a previously undocumented China-aligned threat cluster known as Bronze Sandcastle that has been observed targeting organizations in Asia and Africa since mid-2025.

“The most distinctive technical marker for Bronze Sandcastle is its consistent use of Sandboxie DLL sideloading,” Sophos security researcher Gabor Szappanos said in a post published