User highlighted regions (analysis.highlights)

analysis.highlights: malcat.UserHighlights

The analysis.highlights object is a malcat.UserHighlights instance that gives you access to all the regions highlighted by the user.

Highlighted regions are simple text are regions which were given a title, a note text and a category by the user. They can be viewed in the Hexadecimal view or the Structure/text view (see Highlight/annotate a region). They are saved within a .malcat project. In addition to the UI, highlighted regions can also be parsed and edited programmatically as we will see in this chapter.


Highlighting user regions using the UI

User highlighted region object

A user highlighted region is a file interval which has been given a title, a comment and a category by the user:

class malcat.UserHighlight
__init__(ea, size, title, text='', category=malcat.Category.DEBUG)

Create a new highlighted region instance, for use with the UserHighlights.add() function

address_start = analysis.v2a(0x401000)
address_end = analysis.v2a(0x402000)
c = malcat.UserHighlight(address_start, address_end - address_start, "title", "a comment text", malcat.Category.DEBUG)
if not analysis.highlights.add(c):
    raise ValueError(f"Could not highlight user region [{analysis.ppa(address_start)}-{analysis.ppa(address_end)}[")
param int ea:

the start address of the region to highlight

param int size:

the size of the region

param str title:

the title of the region

param str text:

the comment for the region

param malcat.Category category:

the category of the region

address: int (effective address)

the address of the highlighted region

size: int

the size of the highlighted region

title: str

the title of the highlighted region

content: str

the content of the comment. May contains newlines.


return the value of the title property

Return type:



return the value of the size property

Return type:


The category of a highlighted region dictates its color in the UI and wether it will be displayed or not, depending on Highlighting.

class malcat.Category

This enum describes the category of a note in Malcat.


Note about editing user highlights


Each highlighted region you add gets saved in the list of undoable operations, which can be somewhat expensive if you plan to add thousands of highlighted regions. In general, if you plan to do a lot of modifications (highlighted regions or other types of edits like file writes for instance), you can chose to deactivate undos:

# ... add your highlighted regions, they won't appear in the undo list
for i in range(
     malcat.highlights[i:i+1] = "..."
# ... reactivate undo/redo


Edits which are not recorded to the undo list are invisible to Malcat. It means Malcat will not see that the file has been modified and the UI won’t offer you to save your modifications on quit.

If you stil want to record your edits in the undo/redo but you would like to group them in just one operation, you can do it too:

    # ... add your highlighted regions
for i in range(
     malcat.highlights[i:i+1] = "..."
 analysis.history.undo()     # <-- will undo all highlighted regions in one go