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

Static analysis result for SHA-256 2da9fef1973b5423…

MALICIOUS

Office (OLE) / .XLS

2.07 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-06-19
MD5: 1ed82735a5c87f9d432b4870b59e8421 SHA-1: 29e35abd4367a08e91ec8922d33e396e24a6b4c0 SHA-256: 2da9fef1973b5423e662c91f088ec0b14a524a49184a0471e474a55bdd65a5b3
292 Risk Score

Malware Insights

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

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1566.002 Phishing: Spearphishing Attachment

The sample is an Excel file containing an embedded Equation Editor object that exploits CVE-2017-11882. This object contains a secondary PDF payload, indicated by multiple critical heuristic firings related to polyglot child PDFs and ClamAV detections. The VBA macros are present but contain no executable statements, suggesting the exploit is directly within the OLE object.

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://www.iec.ch

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
a9dfcfbcbdd8cd72f96481f61cc940f471832356314a096f893838ce7704d1e4		 ole-package OLE Ole10Native stream: MBD0021A39B/OlE10natIVe 1821 bytes
stream_001_off00000960.bin
2998a126f4fa11ceb265371a5f7968ec18bc4692a32631a544232dc74040021f		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x960 252488 bytes
stream_007_off0002f015.bin
687dc13e09bd40942bfe2843bb5e4d3d7207221c46649b167abab388296f27c6		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2F015 39292 bytes
icc_00_off00038a50.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e		 pdf-icc-profile PDF ICC profile at offset 0x38A50 3144 bytes
polyglot_child_pdf_off0000b200.pdf
9a322cfadd1e515a42374e13278dbc4d36a8d3388e3a0d4fe211629a97e7ca50		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0xB200 2125824 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0002de00.pdf
a4b1e286a18e79e19448cae38f38afd9ee2c52634b8cac68f36228effb8ffdcd		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x2DE00 1983488 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off000a9a00.pdf
7e60f5fd88ad1ff3d97a8e534853b504534d4f371954f79aade2a331b81d0699		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0xA9A00 1476608 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.