commit d5bf9ae: [Minor] Lua_magic: Minor changes

[Vsevolod Stakhov]

Author: Vsevolod Stakhov
Date: 2021-01-04 16:10:02 +0000
URL: https://github.com/rspamd/rspamd/commit/d5bf9ae28d5d1a06c04da4af303fa8edb2b1f098 (HEAD -> master)

[Minor] Lua_magic: Minor changes

---
 lualib/lua_magic/heuristics.lua | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lualib/lua_magic/heuristics.lua b/lualib/lua_magic/heuristics.lua
index fb0a4b7c2..15d8527fd 100644
--- a/lualib/lua_magic/heuristics.lua
+++ b/lualib/lua_magic/heuristics.lua
@@ -476,17 +476,20 @@ exports.pe_part_heuristic = function(input, log_obj, pos, part)
     return
   end
 
+  -- pe header should start at the offset that is placed in msdos header at position 60..64
   local pe_ptr_bin = input:sub(60, 64)
   if #pe_ptr_bin ~= 4 then
     return
   end
 
-  local pe_ptr = rspamd_util.unpack("<H", pe_ptr_bin)
+  -- it is an LE 32 bit integer
+  local pe_ptr = rspamd_util.unpack("<I4", pe_ptr_bin)
+  -- if pe header magic matches the offset, it is definitely a PE file
   if pe_ptr ~= pos then
     return
   end
 
-  return 'exe',15
+  return 'exe',30
 end
 
 return exports