diff options
Diffstat (limited to 'lualib')
| -rw-r--r-- | lualib/lua_scanners/oletools.lua | 115 |
1 files changed, 69 insertions, 46 deletions
diff --git a/lualib/lua_scanners/oletools.lua b/lualib/lua_scanners/oletools.lua index 1cf3e5f5a..139d1259e 100644 --- a/lualib/lua_scanners/oletools.lua +++ b/lualib/lua_scanners/oletools.lua @@ -35,11 +35,11 @@ local function oletools_check(task, content, digest, rule) local upstream = rule.upstreams:get_upstream_round_robin() local addr = upstream:get_addr() local retransmits = rule.retransmits - local protocol = 'OLEFY/1.0\n' + local protocol = 'OLEFY/1.0\nMethod: oletools\nRspamd-ID: ' .. task:get_uid() .. '\n\n' - local function oletools_callback(err, data, conn) + local function oletools_callback(err, data) - local function oletools_requery() + local function oletools_requery(error) -- set current upstream to fail because an error occurred upstream:fail() @@ -49,7 +49,7 @@ local function oletools_check(task, content, digest, rule) retransmits = retransmits - 1 lua_util.debugm(rule.module_name, task, '%s: Request Error: %s - retries left: %s', - rule.log_prefix, err, retransmits) + rule.log_prefix, error, retransmits) -- Select a different upstream! upstream = rule.upstreams:get_upstream_round_robin() @@ -69,15 +69,14 @@ local function oletools_check(task, content, digest, rule) }) else rspamd_logger.errx(task, '%s: failed to scan, maximum retransmits '.. - 'exceed', rule.log_prefix) - task:insert_result(rule.symbol_fail, 0.0, 'failed to scan and '.. - 'retransmits exceed') + 'exceed - err: %s', rule.log_prefix, error) + task:insert_result(rule.symbol_fail, 0.0, 'failed - err: ' .. error) end end if err then - oletools_requery() + oletools_requery(err) else -- Parse the response @@ -115,21 +114,37 @@ local function oletools_check(task, content, digest, rule) common.save_av_cache(task, digest, rule, 'OK') common.log_clean(task, rule, 'File too small to be scanned for macros') else - oletools_requery() + oletools_requery(result[1].error) end elseif result[3]['return_code'] == 9 then rspamd_logger.warnx(task, '%s: File is encrypted.', rule.log_prefix) elseif result[3]['return_code'] > 6 then rspamd_logger.errx(task, '%s: Error Returned: %s', rule.log_prefix, oletools_rc[result[3]['return_code']]) + rspamd_logger.errx(task, '%s: Error message: %s', + rule.log_prefix, result[2]['message']) + task:insert_result(rule.symbol_fail, 0.0, 'failed - err: ' .. oletools_rc[result[3]['return_code']]) elseif result[3]['return_code'] > 1 then - rspamd_logger.errx(task, '%s: Error Returned: %s', - rule.log_prefix, oletools_rc[result[3]['return_code']]) - oletools_requery() + rspamd_logger.errx(task, '%s: Error message: %s', + rule.log_prefix, result[2]['message']) + oletools_requery(oletools_rc[result[3]['return_code']]) + elseif #result[2]['analysis'] == 0 and #result[2]['macros'] == 0 then + rspamd_logger.warnx(task, '%s: maybe unhandled python or oletools error', rule.log_prefix) + task:insert_result(rule.symbol_fail, 0.0, 'oletools unhandled error') elseif result[2]['analysis'] == 'null' and #result[2]['macros'] == 0 then common.save_av_cache(task, digest, rule, 'OK') common.log_clean(task, rule, 'No macro found') elseif #result[2]['macros'] > 0 then + -- M=Macros, A=Auto-executable, S=Suspicious keywords, I=IOCs, + -- H=Hex strings, B=Base64 strings, D=Dridex strings, V=VBA strings + local m_exist = 'M' + local m_autoexec = '-' + local m_suspicious = '-' + local m_iocs = '-' + local m_hex = '-' + local m_base64 = '-' + local m_dridex = '-' + local m_vba = '-' lua_util.debugm(rule.module_name, task, '%s: filename: %s', rule.log_prefix, result[2]['file']) lua_util.debugm(rule.module_name, task, '%s: type: %s', rule.log_prefix, result[2]['type']) @@ -139,53 +154,60 @@ local function oletools_check(task, content, digest, rule) 'vba_filename: %s', rule.log_prefix, m.code, m.ole_stream, m.vba_filename) end - local macro_autoexec = false - local macro_suspicious = false - local macro_keyword_table = {} + local analysis_keyword_table = {} for _,a in ipairs(result[2]['analysis']) do - if a.type ~= 'AutoExec' or a.type ~= 'Suspicious' then - lua_util.debugm(rule.module_name, task, '%s: threat found - type: %s, keyword: %s, '.. - 'description: %s', rule.log_prefix, a.type, a.keyword, a.description) - end + lua_util.debugm(rule.module_name, task, '%s: threat found - type: %s, keyword: %s, '.. + 'description: %s', rule.log_prefix, a.type, a.keyword, a.description) if a.type == 'AutoExec' then - macro_autoexec = true - if rule.extended == true then - table.insert(macro_keyword_table, a.keyword) - end - elseif a.type == 'Suspicious' - and a.keyword ~= 'Base64 Strings' - and a.keyword ~= 'Hex Strings' - then - macro_suspicious = true - if rule.extended == true then - table.insert(macro_keyword_table, a.keyword) + m_autoexec = 'A' + table.insert(analysis_keyword_table, a.keyword) + elseif a.type == 'Suspicious' then + m_suspicious = 'S' + if a.keyword ~= 'Base64 Strings' and a.keyword ~= 'Hex Strings' + then + table.insert(analysis_keyword_table, a.keyword) end + elseif a.type == 'IOCs' then + m_iocs = 'I' + elseif a.type == 'Hex strings' then + m_hex = 'H' + elseif a.type == 'Base64 strings' then + m_base64 = 'B' + elseif a.type == 'Dridex strings' then + m_dridex = 'D' + elseif a.type == 'VBA strings' then + m_vba = 'V' end end - if macro_autoexec then - table.insert(macro_keyword_table, 'AutoExec') - end - if macro_suspicious then - table.insert(macro_keyword_table, 'Suspicious') - end - - lua_util.debugm(rule.module_name, task, '%s: extended: %s', rule.log_prefix, rule.extended) + --lua_util.debugm(N, task, '%s: analysis_keyword_table: %s', rule.log_prefix, analysis_keyword_table) - if rule.extended == false and macro_autoexec and macro_suspicious then - - lua_util.debugm(rule.module_name, task, '%s: found macro_autoexec and '.. - 'macro_suspicious', rule.log_prefix) - local threat = 'AutoExec+Suspicious' + if rule.extended == false and m_autoexec == 'A' and m_suspicious == 'S' then + -- use single string as virus name + local threat = 'AutoExec + Suspicious (' .. table.concat(analysis_keyword_table, ',') .. ')' + lua_util.debugm(rule.module_name, task, '%s: threat result: %s', rule.log_prefix, threat) common.yield_result(task, rule, threat, rule.default_score) common.save_av_cache(task, digest, rule, threat, rule.default_score) - elseif rule.extended == true and #macro_keyword_table > 0 then + elseif rule.extended == true and #analysis_keyword_table > 0 then + -- report any flags (types) and any most keywords as individual virus name + + local flags = m_exist .. + m_autoexec .. + m_suspicious .. + m_iocs .. + m_hex .. + m_base64 .. + m_dridex .. + m_vba + table.insert(analysis_keyword_table, 1, flags) - common.yield_result(task, rule, macro_keyword_table, rule.default_score) - common.save_av_cache(task, digest, rule, macro_keyword_table, rule.default_score) + lua_util.debugm(rule.module_name, task, '%s: extended threat result: %s', + rule.log_prefix, table.concat(analysis_keyword_table, ',')) + common.yield_result(task, rule, analysis_keyword_table, rule.default_score) + common.save_av_cache(task, digest, rule, analysis_keyword_table, rule.default_score) else common.save_av_cache(task, digest, rule, 'OK') common.log_clean(task, rule, 'Scanned Macro is OK') @@ -193,6 +215,7 @@ local function oletools_check(task, content, digest, rule) else rspamd_logger.warnx(task, '%s: unhandled response', rule.log_prefix) + task:insert_result(rule.symbol_fail, 0.0, 'unhandled response') end end end |