New reference: references/code-virtualization-and-custom-linkers.md
Covers the layer between "packed" and "clean" - manifests whose Application is the
app's own and whose dex is readable, yet a re-signed build dies before user code runs.
Contents: three cheap identification tells (whole classes as native declarations, the
registerNativesForClass/special_clinit pair, SONAME-vs-filename mismatch); the
keep-the-library / delete-the-library deadlock and why both routes fail; the
checker-vs-implementation question that resolves it; the string-redirect technique
(equal-length rewrite of an isolated constant so a loadLibrary call reaches an
already-mapped library, so no offsets move and no death path needs neutralizing);
expected private-loader log shapes; a single-variable experiment to determine whether
the native check reads in-APK certificate material or the PMS-reported signature; and
why a Java-layer signature killer logging success proves nothing.
New tool: scripts/doctor.py
Cheapest first command. Capability report and per-script runnability, with
APKREV_TOOLS support so tools installed off-PATH or as runnable jars are found rather
than reported missing. Surfaces the environment facts that silently poison
experiments: clock skew, leftover adb forward entries, a leftover device proxy, and a
frida process already running on the device (which makes the target look like it
detects instrumentation when nothing has been attached yet).
New tool: scripts/so_constpatch.py
Implements the string-redirect technique. Enforces equal length, refuses to patch a
substring of a longer identifier, reports whether each hit sits in an ELF constant
pool, and patches inside an APK or a bare .so. Field-tested on a real protected
library: find, equal-length replace, unequal-length refusal, multi-hit guard, --force
and absent-name paths all verified.
Updated:
SKILL.md fix question count (ten -> thirteen); index the new reference and
both new scripts; make doctor.py the first step of the workflow;
add the "no packer but still dying" pointer during recon
packers.md cross-reference the new layer so "no packer" is not read as
"editable"
ad-removal.md make log evidence a count rather than an impression (n -> 0 is a
measurement; a tag that goes quiet without reaching zero is a
weaker result)
repack-and-sign.md warn that a full apktool rebuild rewrites obfuscated resource
paths (hundreds of rename pairs) - a tool artifact that must not be
read as breakage - and prefer a dex-only swap when that is the only
edit
pitfalls.md generalize the ServiceLoader example so it is not tied to one
sample's third-party library
README.md document the new files and scripts; document APKREV_TOOLS and the
cross-platform intent
references/native-tamper-and-suicide.md - how a hardened library terminates its own process: the mechanisms and their signatures, how to tell which one actually fires, arranged faults that call nothing (defeating every PLT-level fix), resolving a stub to its symbol, forged section headers, function boundaries from PT_GNU_EH_FRAME, scanner traps, and neutralising by returning rather than spinning.
references/toolchain.md - what to install, non-interactive invocation, GUI-only tools (ask for a human instead of silently substituting a weaker method), version-alignment traps, and working offline.
scripts/elf_plt.py - PLT stub to imported symbol on x86_64 and aarch64 from the relocation table; caller listing; library byte-diff naming each changed stub's symbol. scripts/apk_diff.py - entry-level diff by content hash, so same-size replacements are caught. scripts/native_crash.py - locate a native death from a log or tombstone and flag an arranged fault.
pitfalls P31-P36; SKILL.md gains a decision question, a hard constraint on neutralising terminate paths, and cross-references from packers/native-and-so.
New references (loaded on demand, one topic each):
- packers.md: reading the shell's rejection signal, distinguishing self-inflicted
failures from genuine refusals, mapping the validation boundary via single-variable
tests, component-type rules (providers vs activities), picking a native host
- framework-runtimes.md: identifying Flutter/RN/Unity/Cordova, the wrong-layer trap,
how to tell which layer draws a given UI before committing to a patch direction
- native-and-so.md: host-library selection criteria, DT_NEEDED does-not-call-JNI_OnLoad,
relocation vs page-permission constraints and relocation-free bootstrapping,
replacing Java methods from native code with trampolines and fail-safe guards
- long-task-discipline.md: live record structure, conclusion grading, drift checkpoints,
handover contents, and the opposite failure of over-documenting
Pitfalls: +P18 install reported success but the build was never installed,
+P19 internal signal substituted for the user-visible outcome,
+P20 not-captured treated as not-present, +P21 two changes then attributing the result,
+P22 waiting on something that needs a human to advance.
SKILL.md: index the new references; add a runtime check for layer ownership to Q3;
add long-task rule; strengthen the verify step; add three hard constraints
(user-visible definition of done, no route discarded on compound evidence,
prove the device changed before measuring).
No app names, package names, or sample-specific identifiers anywhere.
inliver233