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author | Vsevolod Stakhov <vsevolod@highsecure.ru> | 2019-09-07 16:13:14 +0100 |
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committer | Vsevolod Stakhov <vsevolod@highsecure.ru> | 2019-09-07 16:13:14 +0100 |
commit | 9dc510171d0a7f308697b70ab22bfe5dafbf29a5 (patch) | |
tree | efad76f96852a57898276b7629ceb56eb7fbf5b4 /lualib/lua_magic | |
parent | 0f4f770639d8ca2f472df95ba6dab6fa27e5772a (diff) | |
download | rspamd-9dc510171d0a7f308697b70ab22bfe5dafbf29a5.tar.gz rspamd-9dc510171d0a7f308697b70ab22bfe5dafbf29a5.zip |
[Project] Lua_magic: Add more office types and clsid based detection
Diffstat (limited to 'lualib/lua_magic')
-rw-r--r-- | lualib/lua_magic/heuristics.lua | 74 | ||||
-rw-r--r-- | lualib/lua_magic/types.lua | 8 |
2 files changed, 64 insertions, 18 deletions
diff --git a/lualib/lua_magic/heuristics.lua b/lualib/lua_magic/heuristics.lua index a61a4abbe..d60c87162 100644 --- a/lualib/lua_magic/heuristics.lua +++ b/lualib/lua_magic/heuristics.lua @@ -28,25 +28,55 @@ local fun = require "fun" local N = "lua_magic" local msoffice_trie local msoffice_patterns = { - doc = [[WordDocument]], - xls = [[Workbook]], - ppt = [[PowerPoint Document]] + doc = {[[WordDocument]]}, + xls = {[[Workbook]], [[Book]]}, + ppt = {[[PowerPoint Document]], [[Current User]]}, + vsd = {[[VisioDocument]]}, } +local msoffice_trie_clsid +local msoffice_clsids = { + doc = {[[0609020000000000c000000000000046]]}, + xls = {[[1008020000000000c000000000000046]], [[2008020000000000c000000000000046]]}, + ppt = {[[108d81649b4fcf1186ea00aa00b929e8]]}, + msg = {[[46f0060000000000c000000000000046]], [[0b0d020000000000c000000000000046]]}, + msi = {[[84100c0000000000c000000000000046]]}, +} +local msoffice_clsid_indexes = {} +local msoffice_patterns_indexes = {} local exports = {} local function compile_msoffice_trie(log_obj) if not msoffice_trie then + -- Directory names local strs = {} - for ext,pat in pairs(msoffice_patterns) do - strs[#strs + 1] = '^' .. - table.concat( - fun.totable( - fun.map(function(c) return c .. [[\x{00}]] end, - fun.iter(pat)))) - msoffice_patterns[ext] = #strs + for ext,pats in pairs(msoffice_patterns) do + for _,pat in ipairs(pats) do + strs[#strs + 1] = '^' .. + table.concat( + fun.totable( + fun.map(function(c) return c .. [[\x{00}]] end, + fun.iter(pat)))) + msoffice_patterns_indexes[#msoffice_patterns_indexes + 1] = ext + + end end msoffice_trie = rspamd_trie.create(strs, rspamd_trie.flags.re) + -- Clsids + strs = {} + for ext,pats in pairs(msoffice_clsids) do + for _,pat in ipairs(pats) do + local hex_table = {} + for i=1,#pat,2 do + local subc = pat:sub(i, i + 1) + hex_table[#hex_table + 1] = string.format('\\x{%s}', subc) + end + strs[#strs + 1] = '^' .. table.concat(hex_table) .. '$' + msoffice_clsid_indexes[#msoffice_clsid_indexes + 1] = ext + + end + end + msoffice_trie_clsid = rspamd_trie.create(strs, rspamd_trie.flags.re) end end @@ -66,7 +96,7 @@ local function detect_ole_format(input, log_obj) bom = '>'; sec_size = bit.bswap(sec_size) end - if sec_size < 7 or sec_size > 9 then + if sec_size < 7 or sec_size > 31 then lua_util.debugm(N, log_obj, "bad sec_size: %s", sec_size) return nil end @@ -85,24 +115,32 @@ local function detect_ole_format(input, log_obj) local function process_dir_entry(offset) local dtype = input:at(offset + 66) - lua_util.debugm(N, log_obj, "dtype: %s", dtype) + lua_util.debugm(N, log_obj, "dtype: %s, offset: %s", dtype, offset) if dtype == 5 then - -- Skip root dentry + -- Extract clsid + local matches = msoffice_trie_clsid:match(input:span(offset + 80, 16)) + if matches then + for n,_ in pairs(matches) do + if msoffice_clsid_indexes[n] then + lua_util.debugm(N, log_obj, "found valid clsid for %s", + msoffice_clsid_indexes[n]) + return true,msoffice_clsid_indexes[n] + end + end + end return true,nil elseif dtype == 2 then local matches = msoffice_trie:match(input:span(offset, 64)) if matches then for n,_ in pairs(matches) do - for ext,num in pairs(msoffice_patterns) do - if num == n then - return true,ext - end + if msoffice_patterns_indexes[n] then + return true,msoffice_patterns_indexes[n] end end end return true,nil - elseif dtype < 5 then + elseif dtype >= 0 and dtype < 5 then -- Bad type return true,nil end diff --git a/lualib/lua_magic/types.lua b/lualib/lua_magic/types.lua index 96c4952a8..8255af663 100644 --- a/lualib/lua_magic/types.lua +++ b/lualib/lua_magic/types.lua @@ -147,10 +147,18 @@ local types = { ct = 'application/vnd.ms-powerpoint', type = 'msoffice' }, + vsd = { + ct = 'application/vnd.visio', + type = 'msoffice' + }, msi = { ct = 'application/x-msi', type = 'executable' }, + msg = { + ct = 'application/vnd.ms-outlook', + type = 'executable' + }, -- other pgp = { ct = 'application/encrypted', |