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import volatility.plugins.taskmods as taskmods |
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import volatility.win32.tasks as tasks |
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import volatility.utils as utils |
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import volatility.debug as debug |
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import volatility.plugins.malware.malfind as malfind |
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import volatility.plugins.linux.pslist as linux_pslist |
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import volatility.plugins.linux.linux_yarascan as linux_yarascan |
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import re |
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import io |
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from struct import unpack, unpack_from |
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from collections import OrderedDict |
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try: |
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import yara |
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has_yara = True |
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except ImportError: |
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has_yara = False |
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elf_plead_sig = { |
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'namespace1' : 'rule elf_plead { \ |
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strings: \ |
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$ioctl = "ioctl TIOCSWINSZ error" \ |
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$class1 = "CPortForwardManager" \ |
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$class2 = "CRemoteShell" \ |
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$class3 = "CFileManager" \ |
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$lzo = { 81 ?? FF 07 00 00 81 ?? 1F 20 00 00 } \ |
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condition: 3 of them}' |
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} |
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CONFIG_PATTERNS = [re.compile("\xBA(...)\x00\xB9\xAA\x01\x00\x00\xBE\x20\x00\x00\x00\xBF(...)\x00", re.DOTALL)] |
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CONFIG_SIZE = 0x1AA |
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KEY_SIZE = 0x20 |
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class elf_pleadConfig(linux_pslist.linux_pslist): |
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"Parse the ELF_PLEAD configuration" |
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@staticmethod |
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def is_valid_profile(profile): |
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return profile.metadata.get('os', 'unknown'), profile.metadata.get('memory_model', '32bit') |
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def get_vma_base(self, task, address): |
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for vma in task.get_proc_maps(): |
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if address >= vma.vm_start and address < vma.vm_end: |
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return vma.vm_start, vma.vm_end |
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return None |
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def filter_tasks(self): |
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tasks = linux_pslist.linux_pslist(self._config).calculate() |
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if self._config.PID is not None: |
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try: |
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pidlist = [int(p) for p in self._config.PID.split(',')] |
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except ValueError: |
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debug.error("Invalid PID {0}".format(self._config.PID)) |
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pids = [t for t in tasks if t.pid in pidlist] |
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if len(pids) == 0: |
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debug.error("Cannot find PID {0}. If its terminated or unlinked, use psscan and then supply --offset=OFFSET".format(self._config.PID)) |
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return pids |
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return tasks |
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def rc4(self, data, key): |
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x = 0 |
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box = range(256) |
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for i in range(256): |
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x = (x + box[i] + ord(key[i % len(key)])) % 256 |
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box[i], box[x] = box[x], box[i] |
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x = 0 |
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y = 0 |
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out = [] |
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for char in data: |
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x = (x + 1) % 256 |
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y = (y + box[x]) % 256 |
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box[x], box[y] = box[y], box[x] |
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out.append(chr(ord(char) ^ box[(box[x] + box[y]) % 256])) |
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return ''.join(out) |
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def parse_config(self, data, start, memory_model): |
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p_data = OrderedDict() |
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for pattern in CONFIG_PATTERNS: |
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if "64" in memory_model: |
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data_base_address = unpack("=Q", data[0x90:0x98])[0] - unpack("=Q", data[0x80:0x88])[0] |
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else: |
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data_base_address = unpack("=I", data[0x60:0x64])[0] - unpack("=I", data[0x58:0x5C])[0] |
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mc = re.search(pattern, data) |
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if mc: |
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config_offset = mc.start(1) |
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config_address = unpack("=I", data[config_offset:config_offset + 4])[0] - data_base_address |
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enc_config = data[config_address:config_address + CONFIG_SIZE] |
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key_offset = mc.start(2) |
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key_address = unpack("=I", data[key_offset:key_offset + 4])[0] - data_base_address |
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key = data[key_address:key_address + KEY_SIZE] |
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if enc_config[0] == "\x00": |
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print("[!] Config area is brank.") |
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else: |
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config = self.rc4(enc_config, key) |
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p_data["ID"] = unpack_from("<8s", config, 0)[0].replace("\0", "") |
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p_data["Unknown1"] = u"0x{0:X}".format(unpack_from("=Q", config, 0x8)[0]) |
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p_data["Unknown2"] = u"0x{0:X}".format(unpack_from("=Q", config, 0x10)[0]) |
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p_data["Unknown3"] = u"0x{0:X}".format(unpack_from("=Q", config, 0x18)[0]) |
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p_data["Port1"] = unpack_from("<H", config, 0x20)[0] |
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p_data["Port2"] = unpack_from("<H", config, 0x22)[0] |
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p_data["Server"] = unpack_from("<384s", config, 0x26)[0].replace("\0", "") |
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p_data["Key"] = u"0x{0:X}".format(unpack_from(">I", config, 0x1A6)[0]) |
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return p_data |
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def calculate(self): |
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if not has_yara: |
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debug.error('Yara must be installed for this plugin.') |
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addr_space = utils.load_as(self._config) |
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os, memory_model = self.is_valid_profile(addr_space.profile) |
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if not os: |
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debug.error('This command does not support the selected profile.') |
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rules = yara.compile(sources=elf_plead_sig) |
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for task in self.filter_tasks(): |
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scanner = linux_yarascan.VmaYaraScanner(task = task, rules = rules) |
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for hit, address in scanner.scan(): |
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start, end = self.get_vma_base(task, address) |
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data = scanner.address_space.zread(start, (end - start) * 2) |
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config_data = [] |
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config_data.append(self.parse_config(data, start, memory_model)) |
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yield task, start, end, hit, memory_model, config_data |
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break |
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def render_text(self, outfd, data): |
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delim = '-' * 70 |
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for task, start, end, malname, memory_model, config_data in data: |
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outfd.write("{0}\n".format(delim)) |
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outfd.write("Process: {0} ({1})\n\n".format(task.comm, task.pid)) |
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outfd.write("[Config Info]\n") |
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for p_data in config_data: |
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for id, param in p_data.items(): |
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outfd.write("{0:<20}: {1}\n".format(id, param)) |
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