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Mini Shell
Mini Shell
"""
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
Copyright © 2019 Cloud Linux Software Inc.
This software is also available under ImunifyAV commercial license,
see <https://www.imunify360.com/legal/eula>
"""
import functools
import glob
import json
import os
import pwd
import re
from collections import defaultdict
from enum import Enum
from logging import getLogger
from typing import Any, Union
import defence360agent.internals.logger
from defence360agent.api import inactivity
from defence360agent.contracts.messages import MessageType
from defence360agent.contracts.plugins import (
MessageSink,
MessageSource,
expect,
)
from defence360agent.model.simplification import run_in_executor
from defence360agent.subsys.panels.hosting_panel import HostingPanel
from defence360agent.utils import Scope, nice_iterator
from imav.malwarelib.config import (
CLEANUP,
CLEANUP_ON_SCHEDULE,
MalwareEvent,
MalwareEventPostponed,
MalwareHitStatus,
MalwareScanResourceType,
MalwareScanType,
NOTIFY,
)
from imav.malwarelib.model import (
MalwareHit,
MalwareHitAlternate,
MalwareScan as MalwareScanModel,
)
from imav.malwarelib.plugins.detached_scan import (
MalwareScanMessageInfo,
)
from imav.malwarelib.scan.mds.report import MalwareDatabaseHitInfo
from imav.malwarelib.subsys.malware import (
HackerTrapHitsSaver,
MalwareAction,
MalwareActionIm360,
)
logger = getLogger(__name__)
class MalwareScanJSONEncoder(json.JSONEncoder):
def default(self, o: Any) -> Any:
if isinstance(o, Enum):
return o.value
return super().default(o)
class StoreMalwareHits(MessageSink, MessageSource):
SCOPE = Scope.AV
malware_action = MalwareAction
_loop, _sink = None, None
async def create_source(self, loop, sink):
self._loop = loop
self._sink = sink
async def create_sink(self, loop):
pass
@expect(MessageType.MalwareScan, async_lock=False)
async def process_hits(self, message):
"""MalwareScan is saved to DB when:
1. Detached scan started - message has no results
2. Any scan finished - message has summary and results
Message without summary means that detached scan is finished
and summary will arrive along with results in another message.
"""
if not message["summary"].get("path"):
return
with inactivity.track.task("store_scan"):
await self._store_scan(message)
@expect(MessageType.MalwareScan)
async def store_log(self, message):
with defence360agent.internals.logger.openMalwareScanLog() as logf:
json.dump(
dict(summary=message["summary"]),
logf,
indent=2,
sort_keys=False,
cls=MalwareScanJSONEncoder,
)
@staticmethod
def _store_hit(scanid, filename, status, resource_type, data):
return MalwareHit.create(
scanid=scanid,
resource_type=resource_type,
owner=data["owner"],
user=data["user"],
size=data["size"],
hash=data["hash"],
orig_file=filename,
type=data["hits"][0]["matches"],
timestamp=data["hits"][0]["timestamp"],
status=status,
malicious=not data["hits"][0]["suspicious"],
)
@staticmethod
def get_outdated_entries(
path_obj: Union[str, list],
scan_type: str = None,
):
"""
Return files that may already not be infected, yet we still
consider them such.
For example, an infected file might have been removed manually.
"""
possibly_infected_statuses = [MalwareHitStatus.FOUND]
paths = [path_obj] if isinstance(path_obj, str) else path_obj
if scan_type == MalwareScanType.REALTIME:
# to avoid duplicates (DEF-10404)
yield from iter(paths)
return
for target_path in paths:
for path in glob.iglob(target_path):
path = os.path.realpath(path)
if (
os.path.isfile(path)
and MalwareHit.select()
.where(
(MalwareHit.orig_file == path)
& (MalwareHit.status.in_(possibly_infected_statuses))
& (
MalwareHit.resource_type
== MalwareScanResourceType.FILE.value
)
)
.first()
):
yield path
else:
scanned_dir = re.escape(path) + r"(/.*|\b)"
yield from (
i.orig_file
for i in MalwareHit.select().where(
(MalwareHit.orig_file.regexp(scanned_dir))
& (
MalwareHit.status.in_(
possibly_infected_statuses
)
)
& (
MalwareHit.resource_type
== MalwareScanResourceType.FILE.value
)
)
)
async def _store_scan(self, message: MessageType.MalwareScan) -> None:
"""Process scan message results.
message: MalwareScan message
"""
summary = message["summary"]
if not summary["started"]:
# Scan is queued/aborted.
return
message_type = MalwareScanMessageInfo(message)
if message_type.is_summary:
if not (
MalwareScanModel.select()
.where(MalwareScanModel.scanid == message["summary"]["scanid"])
.exists()
):
scan = MalwareScanModel.create(
**summary,
resource_type=MalwareScanResourceType.FILE.value,
initiator=message.initiator,
)
scan.total_malicious = 0
scan.save()
else:
logger.warning(
"Scan %s already in database", message["summary"]["scanid"]
)
else:
await self._store_scan_from_results(message)
@classmethod
def _delete_outdated_entries(cls, summary: dict) -> None:
file_patterns = summary.pop("file_patterns", None)
exclude_patterns = summary.pop("exclude_patterns", None)
if (
summary.get("error") is None
and file_patterns is None
and exclude_patterns is None
):
outdated_entries = cls.get_outdated_entries(
summary["path"], scan_type=summary["type"]
)
MalwareHit.delete_hits(outdated_entries)
@staticmethod
async def _process_default_action_results(
hit_data, default_action_results
):
pass
async def _store_scan_from_results(self, message: MessageType.MalwareScan):
summary = message["summary"]
results = message["results"]
scan_id = summary["scanid"]
scan, created = MalwareScanModel.get_or_create(
scanid=scan_id,
defaults={
**summary,
"resource_type": MalwareScanResourceType.FILE.value,
},
)
if not created:
# Detached scan only (second message).
# Update completed time if scan already exists.
scan.completed = summary["completed"]
# get('path') indicates that this is the second message,
# even if they are out of order
if results is not None and summary.get("path") is not None:
self._delete_outdated_entries(summary)
hits = {
hit.orig_file: hit
for hit in MalwareHit.get_hits(files=list(results))
}
postponed_hits = defaultdict(list) # type: dict
total_malicious = 0
def _hit_status_race_detected(hit: MalwareHit, detected_timestamp):
return (
hit.status == MalwareHitStatus.CLEANUP_STARTED
or hit.status
in (
MalwareHitStatus.CLEANUP_DONE,
MalwareHitStatus.CLEANUP_REMOVED,
)
and hit.cleaned_at > detected_timestamp
)
# ignore hits are already processed by another scan
# to avoid send its to CH multiple times
async for file in nice_iterator(tuple(results.keys())):
if file in hits and _hit_status_race_detected(
hits[file], results[file]["hits"][0]["timestamp"]
):
results.pop(file)
malicious_hits = [
MalwareHitAlternate.create(scan.scanid, file, data)
for file, data in results.items()
if not data["hits"][0]["suspicious"]
]
action_results = await self.malware_action.apply_default_action(
hits=malicious_hits,
initiator=message.get("initiator"),
cause=summary["type"],
sink=self._sink,
)
apply_dict = {}
for hit_info, event, action, try_restore in action_results:
apply_dict[hit_info.orig_file] = (event, action, try_restore)
for file, data in results.items():
status = MalwareHitStatus.FOUND
result = None
if file in apply_dict:
(
result,
default_action,
try_restore,
) = apply_dict[file]
# sent to CH
if (
isinstance(result, MalwareEventPostponed)
and result.action == CLEANUP_ON_SCHEDULE
):
# report to CH only well-known `cleanup` / `notify` actions
default_action = (
CLEANUP
if summary["type"] == MalwareScanType.BACKGROUND
else NOTIFY
)
data["default_action"] = default_action
data["try_restore"] = try_restore
total_malicious += 1
if isinstance(result, MalwareEvent):
if result.malware_eliminated:
continue
hit = await run_in_executor(
self._loop,
functools.partial(
self._store_hit,
scan.scanid,
file,
status,
MalwareScanResourceType.FILE.value,
data,
),
)
if isinstance(result, MalwareEventPostponed):
key = (
result.message,
(
result.cause,
result.initiator,
result.post_action,
result.action,
),
)
postponed_hits[key].append(hit)
scan.total_malicious = total_malicious
scan.total_resources = summary["total_files"]
if error := summary.get("error"):
scan.error = error
scan.save()
if self._sink:
for (
(msg_cls, (cause, initiator, post_action, action)),
hits,
) in postponed_hits.items():
if (
action == CLEANUP_ON_SCHEDULE
and summary["type"] != MalwareScanType.BACKGROUND
):
logger.info(
"Skipping auto-cleanup because it's allowed for "
"scheduled scans only"
)
else:
await self._sink.process_message(
msg_cls(
hits=hits,
scan_id=scan_id,
cause=cause,
initiator=initiator,
post_action=post_action,
)
)
await self._process_default_action_results(
results,
{hit.orig_file: event for hit, event, _, _ in action_results},
)
class StoreMalwareHitsIm360(StoreMalwareHits):
SCOPE = Scope.IM360
malware_action = MalwareActionIm360
async def create_sink(self, loop):
await super().create_sink(loop)
await HackerTrapHitsSaver.init()
@staticmethod
async def _process_default_action_results(
hit_data, default_action_results
):
"""Do additional processing for malicious files"""
hacker_trap_hits = []
hacker_trap_sa_hits = []
for path, data in hit_data.items():
result = default_action_results.get(path)
if not isinstance(result, MalwareEvent):
continue
if result.malware_eliminated:
hacker_trap_hits.append(path)
if any(
HackerTrapHitsSaver.STANDALONE_MARK in hit["matches"]
for hit in data["hits"]
):
hacker_trap_sa_hits.append(path)
await HackerTrapHitsSaver.add_hits(hacker_trap_hits)
await HackerTrapHitsSaver.update_sa_hits(hacker_trap_sa_hits, [])
@expect(MessageType.MalwareDatabaseScan)
async def store_db_scan(self, message: MessageType.MalwareDatabaseScan):
if not message.started or message.type is None:
# Scan is queued/aborted or stopped while AVD is not finished yet
return
scan = MalwareScanModel.create(
scanid=message.scan_id,
started=message.started,
completed=message.completed,
type=message.type,
path=message.path,
error=message.error,
total_resources=message.total_resources,
total_malicious=message.total_malicious,
resource_type=MalwareScanResourceType.DB.value,
initiator=message.initiator,
)
if not message.hits:
return
# FIXME: remove this mapping
# when we start to store UID instead of username in the db
panel_users = set(await HostingPanel().get_users())
uid_to_name = {
pw.pw_uid: pw.pw_name
for pw in pwd.getpwall()
if pw.pw_name in panel_users
}
unique_db_hits = MalwareDatabaseHitInfo.get_hits_per_db(message.hits)
self._delete_outdated_db_entries(unique_db_hits)
# apply default action to all hits (to store them in history table)
action_results = await self.malware_action.apply_default_action(
hits=message.hits,
initiator=message.get("initiator"),
cause=message.get("type"),
sink=self._sink,
resource_type=MalwareScanResourceType.DB.value,
)
apply_dict = {}
for hit, event, action, _ in action_results:
apply_dict[hit.path] = (event, action)
postponed_hits = defaultdict(list) # type: dict
for hit_info in unique_db_hits:
result = None
if hit_info.path in apply_dict:
(
result,
default_action,
) = apply_dict[hit_info.path]
# FIXME: DEF-18112 add default_action to hit and send to CH
if isinstance(result, MalwareEvent):
if result.malware_eliminated:
continue
new_hit: MalwareHit = MalwareHit.create(
scanid=scan,
owner=uid_to_name.get(hit_info.owner, hit_info.owner),
user=uid_to_name.get(hit_info.user, hit_info.user),
orig_file=hit_info.path,
type=hit_info.signature,
malicious=True,
hash=None,
size=None,
timestame=None,
status=MalwareHitStatus.FOUND,
cleaned_at=None,
resource_type=MalwareScanResourceType.DB.value,
app_name=hit_info.app_name,
db_host=hit_info.db_host,
db_port=hit_info.db_port,
db_name=hit_info.db_name,
snippet=hit_info.snippet,
)
if isinstance(result, MalwareEventPostponed):
key = (
result.message,
(result.cause, result.initiator, result.post_action),
)
postponed_hits[key].append(new_hit)
if self._sink:
for (
(msg_cls, (cause, initiator, post_action)),
hits,
) in postponed_hits.items():
await self._sink.process_message(
msg_cls(
hits=hits,
scan_id=message.scan_id,
cause=cause,
initiator=initiator,
post_action=post_action,
)
)
@staticmethod
def _delete_outdated_db_entries(hits):
orig_files = [hit.path for hit in hits]
MalwareHit.delete_hits(orig_files)
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