Awesome
HexRays Toolbox
HexRays Toolbox (hxtb) is a powerful set of IDAPython scripts that can be used to find and locate code patterns in binaries, independent from their underlying processor architecture.
Use Cases
- scan binary files for vulnerabilities and variants
- locate code patterns from previously reverse engineered executables in newly decompiled code
- malware variant analysis
- find code similarities across several binaries (i.e. for proving "code theft", license violations, ...)
- find code patterns from binaries compiled for architecture A in binaries compiled for architecture B
- probably a lot more...
The query illustrated by the animation below is an example for how a vulnerability that affected WhatsApp for Android (CVE-2019-3568, libwhatsapp.so) can be located using HexRays Toolbox. This is done by formulating a desired code pattern that is to be located using an IDAPython lambda function. Find the example script .
Requirements
A valid IDA license and a valid HexRays decompiler license per target architecture is required.
Usage
There are several ways of using Hexrays Toolbox, each with a varying degree of flexibility.
- run queries on behalf of hxtb_shell, an interactive GUI
- custom IDAPython scripting
interactive.py
, a script that adds convenience functions to be used with the IDA command line interfaceautomation.py
, a script that processes and runs hxtb queries on a given set of files in batch mode
hxtb-shell
Executing the included hxtb_shell.py
script from within IDA opens a GUI window that can be used to develop, load and run hxtb queries. The screenshot below shows what a query loaded with hxtb-shell may look like.
hxtb-shell also accepts Python expressions that are created by the HRDevHelper plugin's context viewer. They can be copied from it and directly pasted into the hxtb-shell GUI.
Further example queries that can be loaded with hxtb-shell can be found in the hxtbshell_queries
sub-folder included with HexRays Toolbox.
Scripting
Loading hxtb.py
with IDA (Alt-F7) makes functions such as find_expr()
and find_item()
available to both the IDAPython CLI and the script interpreter (Shift-F2). Among others, these functions can be used to run queries on the currently loaded IDA database. Please check out some of the examples shown below.
find_item(ea, q)
find_expr(ea, q)
Positional arguments:
ea: address of a valid function within
the current database
q: lambda function
custom lambda function with the following arguments:
1. cfunc: cfunc_t
2. i/e: cinsn_t/cexpr_t
Returns:
list of query_result_t objects
Example:
find_expr(here(), lambda cf, e: e.op is cot_call)
-> finds and returns all function calls within a current function.
The returned data is a list of query_result_t objects (see hxtb.py).
The returned list can be passed to an instance of the ic_t class,
which causes the data to be displayed by a chooser as follows:
from idaapi import *
import hxtb
hxtb.ic_t(find_expr(here(), lambda cf,e:e.op is cot_call))
Please find the cfunc_t, citem_t, cinsn_t and cexpr_t structures
within hexrays.hpp for further help and details.
Examples
List expressions that compare anything to zero ("x == 0")
cot_eq
/ \
x / \ y
(anything) cot_num --- n.numval() == 0
from idaapi import *
from hxtb import find_expr
query = lambda cfunc, e: e.op is cot_eq and e.y.op is cot_num and e.y.numval() == 0
r = find_expr(here(), query)
for e in r:
print(e)
List (direct) function calls
cot_call
/
x /
cot_obj
from idaapi import *
from hxtb import find_expr
query = lambda cfunc, e: e.op is cot_call and e.x.op is cot_obj
r = find_expr(here(), query)
for e in r:
print(e)
List memcpy calls where "dst" argument is on stack
cot_call --- arg1 is cot_var
/ arg1 is on stack
x /
cot_obj --- name(obj_ea) == 'memcpy'
from idaapi import *
from hxtb import find_expr
r = []
query = lambda cfunc, e: (e.op is cot_call and
e.x.op is cot_obj and
get_name(e.x.obj_ea) == 'memcpy' and
len(e.a) == 3 and
e.a[0].op is cot_var and
cfunc.lvars[e.a[0].v.idx].is_stk_var())
for ea in Functions():
r += find_expr(ea, query)
for e in r:
print(e)
List calls to sprintf(str, fmt, ...) where fmt contains "%s"
cot_call --- arg2 ('fmt') contains '%s'
/
x /
cot_obj --- name(obj_ea) == 'sprintf'
from idaapi import *
from hxtb import find_expr
r = []
query = lambda cfunc, e: (e.op is cot_call and
e.x.op is cot_obj and
get_name(e.x.obj_ea) == 'sprintf' and
len(e.a) >= 2 and
e.a[1].op is cot_obj and
is_strlit(get_flags(get_item_head(e.a[1].obj_ea))) and
b'%s' in get_strlit_contents(e.a[1].obj_ea, -1, 0, STRCONV_ESCAPE))
for ea in Functions():
r += find_expr(ea, query)
for e in r:
print(e)
Show all instructions using signed operators in a list view
from idaapi import *
from hxtb import ic_t
query = lambda cfunc, e: (e.op in
[cot_asgsshr, cot_asgsdiv,
cot_asgsmod, cot_sge,
cot_sle, cot_sgt,
cot_slt, cot_sshr,
cot_sdiv, cot_smod])
ic_t(query)
Show all "if" statements in a list view
from idaapi import *
from hxtb import ic_t
ic_t(lambda cf, i: i.op is cit_if)
Find all loop statements within current db, display result in a list view
from idaapi import *
from hxtb import ic_t, query_db
ic_t(query_db(lambda cf,i: is_loop(i.op)))
Show potential memory copy operations in a list view
from hxtb import ic_t, query_db, find_child_expr
from ida_hexrays import *
find_copy_query = lambda cfunc, i: (i.op is cot_asg and
i.x.op is cot_ptr and
i.y.op is cot_ptr)
find_loop_query = lambda cfunc, i: (is_loop(i.op) and
find_child_expr(cfunc, i, find_copy_query))
ic_t(query_db(find_loop_query))