# Detecting CobaltStrike for Volatility # # LICENSE # Please refer to the LICENSE.txt in the https://github.com/JPCERTCC/MalConfScan/ # # How to use: # 1. locate "cobaltstrikescan.py" in [Volatility_Plugins_Directory] # ex) mv cobaltstrikescan.py /usr/lib/python2.7/dist-packages/volatility/plugins/malware # 2. python vol.py cobaltstrikeconfig -f images.mem --profile=Win7SP1x64 import volatility.plugins.taskmods as taskmods import volatility.win32.tasks as tasks import volatility.utils as utils import volatility.debug as debug import volatility.plugins.malware.malfind as malfind import re from struct import unpack, unpack_from from socket import inet_ntoa from collections import OrderedDict try: import yara has_yara = True except ImportError: has_yara = False cobaltstrike_sig = { 'namespace1' : 'rule CobaltStrike { \ strings: \ $v1 = { 73 70 72 6E 67 00} \ $v2 = { 69 69 69 69 69 69 69 69} \ condition: $v1 and $v2}' } CONF_PATTERNS = [{ 'pattern': '\x69\x68\x69\x68\x69', 'cfg_size': 0x1000, 'cfg_info': [['\x00\x01\x00\x01\x00\x02', 'BeaconType', 0x2], ['\x00\x02\x00\x01\x00\x02', 'Port', 0x2], ['\x00\x03\x00\x02\x00\x04', 'Polling(ms)', 0x4], ['\x00\x04\x00\x02\x00\x04', 'Unknown1', 0x4], ['\x00\x05\x00\x01\x00\x02', 'Jitter', 0x2], ['\x00\x06\x00\x01\x00\x02', 'Maxdns', 0x2], ['\x00\x07\x00\x03\x01\x00', 'Unknown2', 0x100], ['\x00\x08\x00\x03\x01\x00', 'C2Server', 0x100], ['\x00\x09\x00\x03\x00\x80', 'UserAgent', 0x80], ['\x00\x0a\x00\x03\x00\x40', 'HTTP_Method2_Path', 0x40], ['\x00\x0b\x00\x03\x01\x00', 'Unknown3', 0x100], ['\x00\x0c\x00\x03\x01\x00', 'Header1', 0x100], ['\x00\x0d\x00\x03\x01\x00', 'Header2', 0x100], ['\x00\x0e\x00\x03\x00\x40', 'Injection_Process', 0x40], ['\x00\x0f\x00\x03\x00\x80', 'PipeName', 0x80], ['\x00\x10\x00\x01\x00\x02', 'Year', 0x2], ['\x00\x11\x00\x01\x00\x02', 'Month', 0x2], ['\x00\x12\x00\x01\x00\x02', 'Day', 0x2], ['\x00\x13\x00\x02\x00\x04', 'DNS_idle', 0x4], ['\x00\x14\x00\x02\x00\x04', 'DNS_sleep(ms)', 0x2], ['\x00\x1a\x00\x03\x00\x10', 'Method1', 0x10], ['\x00\x1b\x00\x03\x00\x10', 'Method2', 0x10], ['\x00\x1c\x00\x02\x00\x04', 'Unknown4', 0x4], ['\x00\x1d\x00\x03\x00\x40', 'Spawnto_x86', 0x40], ['\x00\x1e\x00\x03\x00\x40', 'Spawnto_x64', 0x40], ['\x00\x1f\x00\x01\x00\x02', 'Unknown5', 0x2], ['\x00\x20\x00\x03\x00\x80', 'Proxy_HostName', 0x80], ['\x00\x21\x00\x03\x00\x40', 'Proxy_UserName', 0x40], ['\x00\x22\x00\x03\x00\x40', 'Proxy_Password', 0x40], ['\x00\x23\x00\x01\x00\x02', 'Proxy_AccessType', 0x2], ['\x00\x24\x00\x01\x00\x02', 'create_remote_thread', 0x2]] }] BEACONTYPE = {0x0: "0 (HTTP)", 0x1: "1 (Hybrid HTTP and DNS)", 0x8: "8 (HTTPS)"} ACCESSTYPE = {0x0: "0 (not use)", 0x1: "1 (use direct connection)", 0x2: "2 (use IE settings)", 0x4: "4 (use proxy server)"} class cobaltstrikeConfig(taskmods.DllList): """Detect processes infected with CobaltStrike malware""" @staticmethod def is_valid_profile(profile): return (profile.metadata.get('os', 'unknown') == 'windows'), profile.metadata.get('memory_model', '32bit') def get_vad_base(self, task, address): for vad in task.VadRoot.traverse(): if address >= vad.Start and address < vad.End: return vad.Start, vad.End return None def decode_config(self, cfg_blob): return "".join(chr(ord(cfg_offset) ^ 0x69) for cfg_offset in cfg_blob) def parse_config(self, cfg_blob, nw): p_data = OrderedDict() for pattern, name, size in nw['cfg_info']: if name.count('Port'): port = unpack_from('>H', cfg_blob, 0xE)[0] p_data[name] = port continue offset = cfg_blob.find(pattern) if offset == -1: p_data[name] = "" continue config_data = cfg_blob[offset + 6:offset + 6 + size] if name.count('Unknown'): p_data[name] = repr(config_data) continue if size == 2: if name.count('BeaconType'): p_data[name] = BEACONTYPE[unpack('>H', config_data)[0]] elif name.count('AccessType'): p_data[name] = ACCESSTYPE[unpack('>H', config_data)[0]] elif name.count('create_remote_thread'): if unpack('>H', config_data)[0] != 0: p_data[name] = "Enable" else: p_data[name] = "Disable" else: p_data[name] = unpack('>H', config_data)[0] elif size == 4: if name.count('DNS_idle'): p_data[name] = inet_ntoa(config_data) else: p_data[name] = unpack('>I', config_data)[0] else: if name.count('Header'): cfg_offset = 3 flag = 0 while 1: if cfg_offset > 255: break else: if config_data[cfg_offset] != '\x00': if config_data[cfg_offset + 1] != '\x00': if flag: name = name + "+" p_data[name] = config_data[(cfg_offset + 1):].split('\x00')[0] cfg_offset = config_data[cfg_offset:].find('\x00\x00\x00') + cfg_offset - 1 flag += 1 else: cfg_offset += 4 continue else: cfg_offset += 4 continue else: p_data[name] = config_data return p_data def calculate(self): if not has_yara: debug.error("Yara must be installed for this plugin") addr_space = utils.load_as(self._config) os, memory_model = self.is_valid_profile(addr_space.profile) if not os: debug.error("This command does not support the selected profile.") rules = yara.compile(sources=cobaltstrike_sig) for task in self.filter_tasks(tasks.pslist(addr_space)): scanner = malfind.VadYaraScanner(task=task, rules=rules) for hit, address in scanner.scan(): vad_base_addr, end = self.get_vad_base(task, address) proc_addr_space = task.get_process_address_space() data = proc_addr_space.zread(vad_base_addr, end - vad_base_addr) config_data = [] for nw in CONF_PATTERNS: cfg_addr = data.find(nw['pattern']) if cfg_addr != -1: break else: continue cfg_blob = data[cfg_addr:cfg_addr + nw['cfg_size']] config_data.append(self.parse_config(self.decode_config(cfg_blob), nw)) yield task, vad_base_addr, end, hit, memory_model, config_data break def render_text(self, outfd, data): delim = '-' * 70 for task, start, end, malname, memory_model, config_data in data: outfd.write("{0}\n".format(delim)) outfd.write("Process: {0} ({1})\n\n".format(task.ImageFileName, task.UniqueProcessId)) outfd.write("[Config Info]\n") for p_data in config_data: for id, param in p_data.items(): outfd.write("{0:<22}: {1}\n".format(id, param))