Xls.Downloader.94c25b356b5a6cac-9978798-0 — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 943e2a06f79d662f…

MALICIOUS

Office (OLE) / .XLS

2.02 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-06-20
MD5: 3851e249cf7d32ba359962fda41f90fb SHA-1: 51ebce9186507f47a1ce2a3a862f457e8872f717 SHA-256: 943e2a06f79d662f5cd0cac37eb6e131b1f4a8bb3dd8941ab0d0494b0cee7e3a
292 Risk Score

Malware Insights

Xls.Downloader.94c25b356b5a6cac-9978798-0 · confidence 95%

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The sample is an Excel file containing a malicious Equation Editor OLE object, which exploits CVE-2017-11882. It also embeds a PDF with suspicious static findings, indicating a multi-stage attack. ClamAV detected this as a downloader, suggesting its primary purpose is to fetch and execute further malicious content.

Heuristics 8

  • 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.
  • 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.
  • 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 http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/iX/1.0/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://www.iec.ch

Extracted artifacts 6

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
99a3202702a2b325f0bdb59754e94c1d9bfc9ddcbca717cc593a050729b7babc		 ole-package OLE Ole10Native stream: MBD000CB2B6/oLe10NaTivE 2015 bytes
stream_003_off0000c415.bin
687dc13e09bd40942bfe2843bb5e4d3d7207221c46649b167abab388296f27c6		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0xC415 39292 bytes
icc_00_off00015e50.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e		 pdf-icc-profile PDF ICC profile at offset 0x15E50 3144 bytes
polyglot_child_pdf_off00011800.pdf
67be6f5789b82d272ae57b2921861bf91b6010456f341ce7b02799efe9eee904		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x11800 2050048 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0008d400.pdf
70afb1699308e648ca9c83cf6737e977c9e7bd689107a1c03868509edee213aa		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x8D400 1543168 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.