Loader basics

Loader opsec quick reference

Disk artifacts

  • When dropping binaries to disk

    • Code Signing

    • Fake signature (LimeLighter, sigthief)

    • Convincing file properties

    • Copyright info

    • Date and time

    • File name

    • Encrypt any malicious code

Execution techniques

  • CreateRemoteThread

    • Remote injection - beacon lives in another process

    • Can blend in, but remember to spoof thread start address. Otherwise will show as 0x0 thread start address

      • You can hook an NTDLL function like in DripLoader to create a thread with a nice looking thread start. However, private bytes will show NTDLL modifications.

    • Memory page will NOT be module backed

  • Early bird

    • Remote injection - beacon lives in another process

    • Evades DLL userland hooks

    • Memory page will NOT be module backed

  • Thread hijack

    • Remote injection - beacon lives in another process

    • Thread will be completely normal on thread creation prior to hijack - memory scanners like to scan at create time

    • Memory page will NOT be module backed

  • Local exec

    • Beacon will live in local process - may be good or bad depending on context

    • No remote process access

    • Memory page MAY be module backed (if you are running from a module on disk e.g. EXE or DLL it will be)

    • Generally less suspicious than remote injection

  • Hollowing variants - run PE in memory

    • Standard hollowing

      • PE image will be of type MEM_COMMIT - not normal

    • Doppelganging

      • PE image will be of type MEM_IMAGE - normal

      • uses TxF

    • Transacted Hollowing/Phantom DLL hollowing

      • PE image will be of type MEM_IMAGE - normal

      • uses TxF

      • Hybrid of doppelganging and standard hollowing

  • Reflective DLL injection

    • Easy to dev payload - no need for actual shellcode

    • IAT hooks can be applied to the reflective DLL instead - stealthier than hooking the loaded copy of NTDLL/Kernel32

-- TO BE CONTINUED --

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