Anti-debug with VirtualAlloc’s write watch

A lesser-known feature of the Windows memory manager is that it can maintain write watches on allocations for debugging and profiling purposes. Passing the MEM_WRITE_WATCH flag to VirtualAlloc “causes the system to track pages that are written to in the allocated region”. TheΒ GetWriteWatch and ResetWriteWatch APIs can be used to manage the watch counter. This… Read More Anti-debug with VirtualAlloc’s write watch

ASUS UEFI Update Driver Physical Memory Read/Write

A short while ago, slipstream/RoL dropped an exploit for the ASUS memory mapping driver (ASMMAP/ASMMAP64) which was vulnerable to complete physical memory access (read/write) to unprivileged users, allowing for local privilege escalation and all sorts of other problems. An aside to this was that there were also IOCTLs available to perform direct I/O operations (in/out… Read More ASUS UEFI Update Driver Physical Memory Read/Write

Talking about Windows drivers at 44CON 2015’s Community Evening

I’ll be speaking at 44CON this year, at the community evening on Wednesday 9th September. The community evening is free to attend – you just need to register to attend if you don’t have a conference ticket. My talk is currently scheduled at 19:45, and I’m speaking about writing Windows drivers, with the goal of… Read More Talking about Windows drivers at 44CON 2015’s Community Evening