Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 605be41d38b0fc66…

MALICIOUS

Office (OLE) / .XLS

994.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-08-20
MD5: 6d9be9e4c3dc9d8b22c00186c6807587 SHA-1: c2aa479f2869b2b83127037c3a759d87fec076e1 SHA-256: 605be41d38b0fc66ffde0e30b185675688228be8f432d62eac89a62774f2c55d
412 Risk Score

Malware Insights

MITRE ATT&CK
T1559.002 Component Object Model Hijacking T1204.002 Malicious File

The file is an XLS document containing an embedded Equation Editor object that exploits CVE-2017-11882. This object is used to deliver a secondary PDF payload which, in turn, contains a direct link to a payload. The ClamAV detection and multiple critical heuristic firings strongly indicate malicious downloader functionality.

Heuristics 11

  • Equation Editor Ole10Native payload — CVE-2017-11882 critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE
    An embedded Microsoft Equation 3.0 object (CLSID 0002CE02-0000-0000-C000-000000000046) carries an Ole10Native packager stream instead of the normal Equation Native/MTEF data. This is the weaponized Equation Editor RCE delivery shape used by CVE-2017-11882 / CVE-2018-0802 maldocs. The payload (font-record overflow + shellcode) is frequently encrypted and the stream name case-scrambled to evade scanners, but an Equation object holding an Ole10Native stream has no benign use.
  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Contains Equation Editor object — related to CVE-2017-11882 / CVE-2018-0802 exploitation, but CLSID presence alone is not the malformed MTEF exploit primitive.
  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • PDF link points directly to executable/archive payload critical PDF_DIRECT_PAYLOAD_LINK
    PDF contains a clickable HTTP(S) URI whose path ends in an executable, script, shortcut, disk image, or archive extension. Documents can legitimately link to installers, so this is a high-risk delivery indicator rather than a standalone exploit fingerprint.
  • ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.94c25b356b5a6cac-9978798-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Clickable PDF combines external action with parser-evasion structure high PDF_ACTION_PARSER_EVASION
    PDF has an external clickable URI together with object graph or xref structures that make parsers disagree, such as divergent duplicate objects, parser divergence, or xref offset mismatch. That combination is stronger than a plain link: the document is both an outward-action carrier and a parser-confusion/evasion sample.
  • PDF paints image(s) but contains no text operators medium PDF_IMAGE_ONLY_LURE
    PDF has 2 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.
  • VBA project contains no executable statements low OLE_VBA_MACROS
    Document contains a VBA project, but extracted modules only contain attributes/options/comments and no executable statements.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://https://www.google.co.in/example.com

Extracted artifacts 8

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7f506327609c082af1cd37dde23bc2c71a000f7d1ef530b6abb66775040a7673
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1206 bytes
ole10native_00.bin
6d77d828de53e2bfce15b3b5a8fd810b3735f7a57ca76e583782eef7ee7947ea
ole-package OLE Ole10Native stream: MBD0007CB50/ole10nATiVE 1384 bytes
polyglot_child_pdf_off00057800.pdf
fdbc8509ca702186987b5777369eeb59b6ccbfd985c2720f2d74c6469361692c
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x57800 659456 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
font_00_sfnt_off00007f7d.bin
68d167e68895a344f3603a4efd0d8438eb8fdebe759cee48f2b4adf75c76c961
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F7D 12100 bytes
font_01_sfnt_off00009d95.bin
50551000b9f90b3f445ee94749557d9ddf96697a74984b3ccf3d2bae66910750
pdf-font-stream PDF embedded font (sfnt) at offset 0x9D95 15820 bytes
polyglot_child_pdf_off00001000.pdf
e0b1ed35f884f1ca838ffcc65c47d23e8b84d494ed3bb0e81744cb762ab8c8a3
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1000 1013760 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off00006000.pdf
cd1ebfb31445f0c3749d6b64b35ed3a5c56195bb1bf8c8b81fbd470513d57010
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6000 993280 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0000e200.pdf
968053552149331d6db66346ac1c0739e983eca31f53e639ae928179be8c7b3d
polyglot-child-pdf Secondary PDF body inside ole container at offset 0xE200 960000 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely