Chrome extensions can be downloaded either from the main window or from the analysis workspace action.
The CRX Format package is exposed to the SDK:
from Pro.Core import *
from Pkg.CRX import *
def parseCRX(fname):
c = createContainerFromFile(fname)
if c.isNull():
return
obj = CRXObject()
if not obj.Load(c):
return
range = obj.GetArchiveRange()
if range:
# prints out the range of the embedded Zip archive
print("content offset:", hex(range.offset), "size:", hex(range.size))

