OSError: seek to offset N is outside window

[tr4px]

The following two malicious Mach-O files trigger an exception when loading the file:

• https://www.virustotal.com/gui/file/f1c8225600cfbf3aee42f414afa8a4978b43b8df2b480753807e461b3afe1ff5
• https://www.virustotal.com/gui/file/bfb385e9fa6204325a00900406a577db6fcfd2db071370f16cb8da9208c36d1c

Using version https://pypi.org/project/macholib/1.16.3/

08ebd550228fbcd8c85494192203347cf94cf251.zip (password "infected")
1491813dd0ead90e9107f58f6f2d2a71fd909e96.zip (password "infected")

Traceback (most recent call last):
  File "/home/user/mach.py", line 301, in parse
    mach = MachO(filepath)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 121, in __init__
    self.load(fp)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 136, in load
    self.load_header(fh, 0, size)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 171, in load_header
    hdr = MachOHeader(
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 229, in __init__
    self.load(fh)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 316, in load
    fh.seek(seg.offset)
  File "/usr/local/lib/python3.8/dist-packages/macholib/util.py", line 91, in seek
    self._checkwindow(seekto, "seek")
  File "/usr/local/lib/python3.8/dist-packages/macholib/util.py", line 76, in _checkwindow
    raise IOError(
OSError: seek to offset 5673216 is outside window [0, 5165538]

Traceback (most recent call last):
  File "/home/user/mach.py", line 301, in parse
    mach = MachO(filepath)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 121, in __init__
    self.load(fp)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 136, in load
    self.load_header(fh, 0, size)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 171, in load_header
    hdr = MachOHeader(
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 229, in __init__
    self.load(fh)
  File "/usr/local/lib/python3.8/dist-packages/macholib/MachO.py", line 316, in load
    fh.seek(seg.offset)
  File "/usr/local/lib/python3.8/dist-packages/macholib/util.py", line 91, in seek
    self._checkwindow(seekto, "seek")
  File "/usr/local/lib/python3.8/dist-packages/macholib/util.py", line 76, in _checkwindow
    raise IOError(
OSError: seek to offset 2390848 is outside window [0, 123440]