diff --git a/testing/mozharness/mozharness/base/script.py b/testing/mozharness/mozharness/base/script.py
index e5d8cebb96d1..38f3a4efb05d 100755
--- a/testing/mozharness/mozharness/base/script.py
+++ b/testing/mozharness/mozharness/base/script.py
@@ -15,8 +15,11 @@ import codecs
 from contextlib import contextmanager
 import datetime
 import errno
+import fnmatch
+import functools
 import gzip
 import inspect
+import itertools
 import os
 import platform
 import pprint
@@ -25,9 +28,11 @@ import shutil
 import socket
 import subprocess
 import sys
+import tarfile
 import time
 import traceback
 import urllib2
+import zipfile
 import httplib
 import urlparse
 import hashlib
@@ -47,10 +52,10 @@ except ImportError:
 
 from mozprocess import ProcessHandler
 from mozharness.base.config import BaseConfig
-from mozharness.base.errors import ZipErrorList
 from mozharness.base.log import SimpleFileLogger, MultiFileLogger, \
     LogMixin, OutputParser, DEBUG, INFO, ERROR, FATAL
 
+
 def platform_name():
     pm = PlatformMixin()
 
@@ -453,7 +458,7 @@ class ScriptMixin(PlatformMixin):
             **retry_args
         )
 
-    def download_unzip(self, url, parent_dir, target_unzip_dirs=None, halt_on_failure=True):
+    def download_unzip(self, url, parent_dir, target_unzip_dirs=None):
         """Generic method to download and extract a zip file.
 
         The downloaded file will always be saved to the working directory and is not getting
@@ -465,27 +470,13 @@ class ScriptMixin(PlatformMixin):
                               be extracted to.
             target_unzip_dirs (list, optional): directories inside the zip file to extract.
                                                 Defaults to `None`.
-            halt_on_failure (bool, optional): whether or not to redefine the
-                                              log level as `FATAL` on errors. Defaults to True.
 
         """
         dirs = self.query_abs_dirs()
         zipfile = self.download_file(url, parent_dir=dirs['abs_work_dir'],
                                      error_level=FATAL)
 
-        command = self.query_exe('unzip', return_type='list')
-        # Always overwrite to not get an input in a hidden pipe if files already exist
-        command.extend(['-q', '-o', zipfile, '-d', parent_dir])
-        if target_unzip_dirs:
-            command.extend(target_unzip_dirs)
-        # TODO error_list: http://www.info-zip.org/mans/unzip.html#DIAGNOSTICS
-        # unzip return code 11 is 'no matching files were found'
-        self.run_command(command,
-                         error_list=ZipErrorList,
-                         halt_on_failure=halt_on_failure,
-                         fatal_exit_code=3,
-                         success_codes=[0, 11],
-                         )
+        self.unpack(zipfile, parent_dir, target_unzip_dirs)
 
     def load_json_url(self, url, error_level=None, *args, **kwargs):
         """ Returns a json object from a url (it retries). """
@@ -1105,7 +1096,7 @@ class ScriptMixin(PlatformMixin):
             output_timeout (int): amount of seconds to wait for output before
               the process is killed.
             fatal_exit_code (int, optional): call `self.fatal` if the return value
-              of the command is not on in `success_codes`. Defaults to 2.
+              of the command is not in `success_codes`. Defaults to 2.
             error_level (str, optional): log level name to use on error. Defaults
               to `ERROR`.
             **kwargs: Arbitrary keyword arguments.
@@ -1397,26 +1388,75 @@ class ScriptMixin(PlatformMixin):
                 self.log(msg, error_level=error_level)
         os.utime(file_name, times)
 
-    def unpack(self, filename, extract_to):
-        '''
+    def unpack(self, filename, extract_to, extract_dirs=None,
+               error_level=ERROR, halt_on_failure=True, fatal_exit_code=2,
+               verbose=False):
+        """
         This method allows us to extract a file regardless of its extension
 
         Args:
             filename (str): filename of the compressed file.
             extract_to (str): where to extract the compressed file.
-        '''
-        # XXX: Make sure that filename has a extension of one of our supported file formats
-        m = re.search('\.tar\.(bz2|gz)$', filename)
-        if m:
-            command = self.query_exe('tar', return_type='list')
-            tar_cmd = "jxfv"
-            if m.group(1) == "gz":
-                tar_cmd = "zxfv"
-            command.extend([tar_cmd, filename, "-C", extract_to])
-            self.run_command(command, halt_on_failure=True)
+            extract_dirs (list, optional): directories inside the archive file to extract.
+                                           Defaults to `None`.
+            halt_on_failure (bool, optional): whether or not to redefine the
+                                              log level as `FATAL` on errors. Defaults to True.
+            fatal_exit_code (int, optional): call `self.fatal` if the return value
+              of the command is not in `success_codes`. Defaults to 2.
+            verbose (bool, optional): whether or not extracted content should be displayed.
+                                      Defaults to False.
+
+        Raises:
+            IOError: on `filename` file not found.
+
+        """
+        def _filter_entries(namelist):
+            """Filter entries of the archive based on the specified list of to extract dirs."""
+            filter_partial = functools.partial(fnmatch.filter, namelist)
+            for entry in itertools.chain(*map(filter_partial, extract_dirs or ['*'])):
+                yield entry
+
+        if not os.path.isfile(filename):
+            raise IOError('Could not find file to extract: %s' % filename)
+
+        level = FATAL if halt_on_failure else error_level
+
+        if zipfile.is_zipfile(filename):
+            try:
+                self.info('Using ZipFile to extract {} to {}'.format(filename, extract_to))
+                with zipfile.ZipFile(filename) as bundle:
+                    for entry in _filter_entries(bundle.namelist()):
+                        if verbose:
+                            self.info(' %s' % entry)
+                        bundle.extract(entry, path=extract_to)
+
+                        # ZipFile doesn't preserve permissions during extraction:
+                        # http://bugs.python.org/issue15795
+                        fname = os.path.realpath(os.path.join(extract_to, entry))
+                        mode = bundle.getinfo(entry).external_attr >> 16 & 0x1FF
+                        # Only set permissions if attributes are available. Otherwise all
+                        # permissions will be removed eg. on Windows.
+                        if mode:
+                            os.chmod(fname, mode)
+            except zipfile.BadZipfile as e:
+                self.log('%s (%s)' % (e.message, filename),
+                         level=level, exit_code=fatal_exit_code)
+
+        # Bug 1211882 - is_tarfile cannot be trusted for dmg files
+        elif tarfile.is_tarfile(filename) and not filename.lower().endswith('.dmg'):
+            try:
+                self.info('Using TarFile to extract {} to {}'.format(filename, extract_to))
+                with tarfile.open(filename) as bundle:
+                    for entry in _filter_entries(bundle.getnames()):
+                        if verbose:
+                            self.info(' %s' % entry)
+                        bundle.extract(entry, path=extract_to)
+            except tarfile.TarError as e:
+                self.log('%s (%s)' % (e.message, filename),
+                         level=level, exit_code=fatal_exit_code)
         else:
-            # XXX implement
-            pass
+            self.log('No extraction method found for: %s' % filename,
+                     level=level, exit_code=fatal_exit_code)
 
 
 def PreScriptRun(func):
diff --git a/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py b/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
index b38971b1a888..1acec5464689 100644
--- a/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
+++ b/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
@@ -300,53 +300,6 @@ class FirefoxUITests(TestingMixin, VCSToolsScript):
             env=self.query_env(),
         )
 
-    def download_unzip(self, url, parent_dir, target_unzip_dirs=None, halt_on_failure=True):
-        """Overwritten method from BaseScript until bug 1258539 is fixed.
-
-        The downloaded file will always be saved to the working directory and is not getting
-        deleted after extracting.
-
-        Args:
-            url (str): URL where the file to be downloaded is located.
-            parent_dir (str): directory where the downloaded file will
-                              be extracted to.
-            target_unzip_dirs (list, optional): directories inside the zip file to extract.
-                                                Defaults to `None`.
-            halt_on_failure (bool, optional): whether or not to redefine the
-                                              log level as `FATAL` on errors. Defaults to True.
-
-        """
-        import fnmatch
-        import itertools
-        import functools
-        import zipfile
-
-        def _filter_entries(namelist):
-            """Filter entries of the archive based on the specified list of extract_dirs."""
-            filter_partial = functools.partial(fnmatch.filter, namelist)
-            for entry in itertools.chain(*map(filter_partial, target_unzip_dirs or ['*'])):
-                yield entry
-
-        dirs = self.query_abs_dirs()
-        zip = self.download_file(url, parent_dir=dirs['abs_work_dir'],
-                                 error_level=FATAL)
-
-        try:
-            self.info('Using ZipFile to extract {0} to {1}'.format(zip, parent_dir))
-            with zipfile.ZipFile(zip) as bundle:
-                for entry in _filter_entries(bundle.namelist()):
-                    bundle.extract(entry, path=parent_dir)
-
-                    # ZipFile doesn't preserve permissions: http://bugs.python.org/issue15795
-                    fname = os.path.realpath(os.path.join(parent_dir, entry))
-                    mode = bundle.getinfo(entry).external_attr >> 16 & 0x1FF
-                    # Only set permissions if attributes are available.
-                    if mode:
-                        os.chmod(fname, mode)
-        except zipfile.BadZipfile as e:
-            self.log('{0} ({1})'.format(e.message, zip),
-                     level=FATAL, exit_code=2)
-
 
 class FirefoxUIFunctionalTests(FirefoxUITests):
 
diff --git a/testing/mozharness/mozharness/mozilla/testing/talos.py b/testing/mozharness/mozharness/mozilla/testing/talos.py
index 9daf61a3bd95..26f828121b45 100755
--- a/testing/mozharness/mozharness/mozilla/testing/talos.py
+++ b/testing/mozharness/mozharness/mozilla/testing/talos.py
@@ -285,9 +285,13 @@ class Talos(TestingMixin, MercurialScript, BlobUploadMixin):
         src_talos_webdir = os.path.join(self.talos_path, 'talos')
 
         if self.query_pagesets_url():
-            self.info("Downloading pageset...")
+            self.info('Downloading pageset...')
+            dirs = self.query_abs_dirs()
             src_talos_pageset = os.path.join(src_talos_webdir, 'tests')
-            self.download_unzip(self.pagesets_url, src_talos_pageset)
+            archive = self.download_file(self.pagesets_url, parent_dir=dirs['abs_work_dir'])
+            unzip = self.query_exe('unzip')
+            unzip_cmd = [unzip, '-q', '-o', archive, '-d', src_talos_pageset]
+            self.run_command(unzip_cmd, halt_on_failure=True)
 
     # Action methods. {{{1
     # clobber defined in BaseScript
diff --git a/testing/mozharness/mozharness/mozilla/testing/testbase.py b/testing/mozharness/mozharness/mozilla/testing/testbase.py
index 5e0fddb58f10..5467af12f237 100755
--- a/testing/mozharness/mozharness/mozilla/testing/testbase.py
+++ b/testing/mozharness/mozharness/mozilla/testing/testbase.py
@@ -401,17 +401,6 @@ You can set this by:
         if message:
             self.fatal(message + "Can't run download-and-extract... exiting")
 
-        if self.config.get("developer_mode") and self._is_darwin():
-            # Bug 1066700 only affects Mac users that try to run mozharness locally
-            version = self._query_binary_version(
-                    regex=re.compile("UnZip\ (\d+\.\d+)\ .*", re.MULTILINE),
-                    cmd=[self.query_exe('unzip'), '-v']
-            )
-            if not version >= 6:
-                self.fatal("We require a more recent version of unzip to unpack our tests.zip files.\n"
-                        "You are currently using version %s. Please update to at least 6.0.\n"
-                        "You can visit http://www.info-zip.org/UnZip.html" % version)
-
     def _read_packages_manifest(self):
         dirs = self.query_abs_dirs()
         source = self.download_file(self.test_packages_url,
diff --git a/testing/mozharness/test/helper_files/archives/archive.tar b/testing/mozharness/test/helper_files/archives/archive.tar
new file mode 100644
index 000000000000..1dc094198f31
Binary files /dev/null and b/testing/mozharness/test/helper_files/archives/archive.tar differ
diff --git a/testing/mozharness/test/helper_files/archives/archive.tar.bz2 b/testing/mozharness/test/helper_files/archives/archive.tar.bz2
new file mode 100644
index 000000000000..c393ea4b881c
Binary files /dev/null and b/testing/mozharness/test/helper_files/archives/archive.tar.bz2 differ
diff --git a/testing/mozharness/test/helper_files/archives/archive.tar.gz b/testing/mozharness/test/helper_files/archives/archive.tar.gz
new file mode 100644
index 000000000000..0fbfa39b1c76
Binary files /dev/null and b/testing/mozharness/test/helper_files/archives/archive.tar.gz differ
diff --git a/testing/mozharness/test/helper_files/archives/archive.zip b/testing/mozharness/test/helper_files/archives/archive.zip
new file mode 100644
index 000000000000..aa2fb34c1658
Binary files /dev/null and b/testing/mozharness/test/helper_files/archives/archive.zip differ
diff --git a/testing/mozharness/test/helper_files/archives/archive_invalid_filename.zip b/testing/mozharness/test/helper_files/archives/archive_invalid_filename.zip
new file mode 100644
index 000000000000..20bdc5acdf11
Binary files /dev/null and b/testing/mozharness/test/helper_files/archives/archive_invalid_filename.zip differ
diff --git a/testing/mozharness/test/helper_files/archives/reference/bin/script.sh b/testing/mozharness/test/helper_files/archives/reference/bin/script.sh
new file mode 100755
index 000000000000..134f2933c94b
--- /dev/null
+++ b/testing/mozharness/test/helper_files/archives/reference/bin/script.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo Hello world!
diff --git a/testing/mozharness/test/helper_files/archives/reference/lorem.txt b/testing/mozharness/test/helper_files/archives/reference/lorem.txt
new file mode 100644
index 000000000000..d2cf010d36ff
--- /dev/null
+++ b/testing/mozharness/test/helper_files/archives/reference/lorem.txt
@@ -0,0 +1 @@
+Lorem ipsum dolor sit amet.
diff --git a/testing/mozharness/test/helper_files/create_archives.sh b/testing/mozharness/test/helper_files/create_archives.sh
new file mode 100755
index 000000000000..314b55d27685
--- /dev/null
+++ b/testing/mozharness/test/helper_files/create_archives.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+# Script to auto-generate the different archive types under the archives directory.
+
+cd archives
+
+rm archive.*
+
+tar cf archive.tar -C reference .
+gzip -fk archive.tar >archive.tar.gz
+bzip2 -fk archive.tar >archive.tar.bz2
+cd reference && zip ../archive.zip -r * && cd ..
diff --git a/testing/mozharness/test/test_base_script.py b/testing/mozharness/test/test_base_script.py
index 1e2e22c606e7..02bb37a7456f 100644
--- a/testing/mozharness/test/test_base_script.py
+++ b/testing/mozharness/test/test_base_script.py
@@ -2,6 +2,8 @@ import gc
 import mock
 import os
 import re
+import shutil
+import tempfile
 import types
 import unittest
 PYWIN32 = False
@@ -19,6 +21,9 @@ from mozharness.base.log import DEBUG, INFO, WARNING, ERROR, CRITICAL, FATAL, IG
 import mozharness.base.script as script
 from mozharness.base.config import parse_config_file
 
+
+here = os.path.dirname(os.path.abspath(__file__))
+
 test_string = '''foo
 bar
 baz'''
@@ -31,10 +36,12 @@ class CleanupObj(script.ScriptMixin, log.LogMixin):
         self.config = {'log_level': ERROR}
 
 
-def cleanup():
+def cleanup(files=None):
+    files = files or []
+    files.extend(('test_logs', 'test_dir', 'tmpfile_stdout', 'tmpfile_stderr'))
     gc.collect()
     c = CleanupObj()
-    for f in ('test_logs', 'test_dir', 'tmpfile_stdout', 'tmpfile_stderr'):
+    for f in files:
         c.rmtree(f)
 
 
@@ -56,12 +63,13 @@ class TestScript(unittest.TestCase):
     def setUp(self):
         cleanup()
         self.s = None
+        self.tmpdir = tempfile.mkdtemp(suffix='.mozharness')
 
     def tearDown(self):
         # Close the logfile handles, or windows can't remove the logs
         if hasattr(self, 's') and isinstance(self.s, object):
             del(self.s)
-        cleanup()
+        cleanup([self.tmpdir])
 
     # test _dump_config_hierarchy() when --dump-config-hierarchy is passed
     def test_dump_config_hierarchy_valid_files_len(self):
@@ -251,6 +259,38 @@ class TestScript(unittest.TestCase):
         self.assertTrue(error_logsize > 0,
                         msg="error list not working properly")
 
+    def test_unpack(self):
+        self.s = get_debug_script_obj()
+
+        archives_path = os.path.join(here, 'helper_files', 'archives')
+
+        # Test basic decompression
+        for archive in ('archive.tar', 'archive.tar.bz2', 'archive.tar.gz', 'archive.zip'):
+            self.s.unpack(os.path.join(archives_path, archive), self.tmpdir)
+            self.assertIn('script.sh', os.listdir(os.path.join(self.tmpdir, 'bin')))
+            self.assertIn('lorem.txt', os.listdir(self.tmpdir))
+            shutil.rmtree(self.tmpdir)
+
+        # Test permissions for extracted entries from zip archive
+        self.s.unpack(os.path.join(archives_path, 'archive.zip'), self.tmpdir)
+        file_stats = os.stat(os.path.join(self.tmpdir, 'bin', 'script.sh'))
+        orig_fstats = os.stat(os.path.join(archives_path, 'reference', 'bin', 'script.sh'))
+        self.assertEqual(file_stats.st_mode, orig_fstats.st_mode)
+        shutil.rmtree(self.tmpdir)
+
+        # Test extract specific dirs only
+        self.s.unpack(os.path.join(archives_path, 'archive.zip'), self.tmpdir,
+                      extract_dirs=['bin/*'])
+        self.assertIn('bin', os.listdir(self.tmpdir))
+        self.assertNotIn('lorem.txt', os.listdir(self.tmpdir))
+        shutil.rmtree(self.tmpdir)
+
+        # Test for invalid filenames (Windows only)
+        if PYWIN32:
+            with self.assertRaises(IOError):
+                self.s.unpack(os.path.join(archives_path, 'archive_invalid_filename.zip'),
+                              self.tmpdir)
+
 
 # TestHelperFunctions {{{1
 class TestHelperFunctions(unittest.TestCase):