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# Detecting Datper for Volatility
#
# LICENSE
# Please refer to the LICENSE.txt in the https://github.com/JPCERTCC/MalConfScan/
#
# How to use:
# 1. cd "Volatility Folder"
# 2. mv datperscan.py volatility/plugins/malware
# 3. python vol.py datperconfig -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
import pefile
from struct import unpack, unpack_from
from collections import OrderedDict
try:
import yara
has_yara = True
except ImportError:
has_yara = False
datper_sig = {
'namespace1' : 'rule Datper { \
strings: \
$a1 = { E8 03 00 00 } \
$b1 = "|||" \
$c1 = "Content-Type: application/x-www-form-urlencoded" \
$delphi = "Borland\\Delphi" ascii wide \
$push7530h64 = { C7 C1 30 75 00 00 } \
$push7530h = { 68 30 75 00 00 } \
condition: $a1 and $b1 and $c1 and $delphi and ($push7530h64 or $push7530h)}'
}
CONFIG_PATTERNS = [
re.compile("\xB8(....)(\xBA\xE8\x03\x00\x00)", re.DOTALL), # mov eax, qword ptr config_offset;mov edx 0x3e8
re.compile("\xB8(....)(\x75\x00\xBA\xE8\x03\x00\x00)", re.DOTALL), # mov eax, qword ptr config_offset;jnz short $+2;mov edx 0x3e8
re.compile("\x48\x8D\x0D(....)(\xC7\xC2\xE8\x03\x00\x00)", re.DOTALL) # lea rax, qword ptr config_offset;mov edx 0x3e8
]
RC4KEY = ["d4n[6h}8o<09,d(21i`t4n$]hx%.h,hd",
"B3uT16@qs\l,!GdSevH=Y(;7Ady$jl\e",
"V7oT1@@qr\\t,!GOSKvb=p(;3Akb$rl\\a"
]
idx_list = {
0: "ID",
1: "URL",
2: "Sleep time(s)",
3: "Mutex",
4: "Proxy server",
5: "Proxy port",
6: "Unknown",
7: "Unknown",
8: "Startup time(h)",
9: "End time(h)",
10: "Unknown",
11: "User-Agent",
12: "RSA key(e + modules)"
}
CONFSIZE = 0x3F8
config_delimiter = ["|||", "[|-]"]
class datperConfig(taskmods.DllList):
"""Parse the Datper configuration"""
@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
# Custom RC4 use sbox seed
def custom_rc4(self, data, key, box_seed):
x = 0
box = range(256)
if box_seed != 0:
for i in range(256):
box[i] = (i + box_seed) & 0xFF
for i in range(256):
x = (x + box[i] + ord(key[i % len(key)])) % 256
box[i], box[x] = box[x], box[i]
x = 0
y = 0
out = []
for char in data:
x = (x + 1) % 256
y = (y + box[x]) % 256
box[x], box[y] = box[y], box[x]
out.append(chr(ord(char) ^ box[(box[x] + box[y]) % 256]))
return ''.join(out)
def get_config_data_64(self, data, pe):
for pattern in CONFIG_PATTERNS:
m = re.search(pattern, data)
if m:
#print("found pattern")
rva_offset_config = pe.get_rva_from_offset(m.start(2)) + unpack("<L", data[m.start(1):m.start(1) + 4])[0]
config = pe.get_memory_mapped_image()[rva_offset_config:rva_offset_config + CONFSIZE]
return config
return None
def get_config_data_32(self, data, pe, start):
for pattern in CONFIG_PATTERNS:
m = re.search(pattern, data)
if m:
#print("found pattern")
rva_offset_config = unpack("<L", data[m.start(1):m.start(1) + 4])[0]
rva_config = rva_offset_config - start
config = data[rva_config:rva_config + CONFSIZE]
return config
return None
def decompress(self, data):
if ord(data[0]) == 0x80:
return data[1:]
length = unpack("<H", data[:2])[0]
if length > len(data[2:]):
print("[!] invalid length")
return ""
data = data[2:2 + length]
tmp = ""
for i, c in enumerate(data):
val = (((i >> 5) + (i << 7) + length + ~i) & 0xFF)
tmp += chr(ord(c) ^ (((i >> 5) + (i << 7) + length + ~i) & 0xFF))
tmp = map(ord, list(tmp))[1:]
i = 0
block_len = 16
dec = ""
try:
while i < len(tmp):
if block_len == 16:
block_flag = (tmp[i] << 8) + tmp[i + 1]
block_len = 0
i += 2
if block_flag & (0x8000 >> block_len) != 0:
char_flag = (tmp[i + 1] >> 4) + (16 * tmp[i])
if char_flag != 0:
loop_count = (tmp[i + 1] & 0xF) + 3
for n in range(loop_count):
dec += dec[-char_flag]
i += 2
else:
loop_count = (tmp[i + 1] << 8) + tmp[i + 2] + 16
for n in range(loop_count):
#data += chr(tmp[i + 3])
pass
i += 4
else:
dec += chr(tmp[i])
i += 1
block_len += 1
except:
raise
return ""
return dec
def decrypt(self, dec):
decrypted_len = len(dec)
decomp = []
processed_len = 0
while (decrypted_len > processed_len):
enc_compressed_len = unpack("<H", dec[processed_len:processed_len + 2])[0]
enc_compressed = dec[processed_len + 2:processed_len + 2 + enc_compressed_len]
if enc_compressed_len > len(enc_compressed):
break
processed_len += enc_compressed_len + 2
tmp = []
for i in range(enc_compressed_len):
xor_key = (i >> 5) & 0xff
xor_key += (i << 7) & 0xff
xor_key += enc_compressed_len
xor_key += ~i
xor_key = xor_key & 0xff
tmp.append(chr(ord(enc_compressed[i]) ^ xor_key))
compressed = "".join(tmp)
decompressed = self.decompress(compressed)
decomp.append(decompressed)
return "".join(decomp)
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=datper_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 = []
try:
pe = pefile.PE(data=data)
except:
# print("[!] could not parse as a PE file")
break
config_size = CONFSIZE
if pe.FILE_HEADER.Machine in (pefile.MACHINE_TYPE['IMAGE_FILE_MACHINE_IA64'], pefile.MACHINE_TYPE['IMAGE_FILE_MACHINE_AMD64']):
enc = self.get_config_data_64(data, pe)
else:
enc = self.get_config_data_32(data, pe, vad_base_addr)
dec = ""
for key in RC4KEY:
for rc4key_seed in range(0xFF):
dec = self.custom_rc4(enc, key, rc4key_seed)
dec = self.decrypt(dec)
for dline in config_delimiter:
if dline in dec:
break
else:
continue
break
else:
continue
break
if dec == "":
dec = self.decrypt(enc)
for dline in config_delimiter:
if dline in dec:
key = "NULL"
rc4key_seed = "NULL"
break
p_data = OrderedDict()
if dec != "":
p_data["RC4 key"] = key
p_data["RC4 Sbox seed"] = rc4key_seed
p_data["Config delimiter"] = dline
idx = 0
for e in (dec.split(dline)):
try:
p_data[idx_list[idx]] = e
except:
p_data["Unknown " + str(idx)] = e
idx += 1
else:
outfd.write("[!] failed to decrypt\n")
config_data.append(p_data)
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:<16}: {1}\n".format(id, param))
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