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

Static analysis result for SHA-256 513307acdc3194cc…

MALICIOUS

Office (OLE) / .XLS

2.00 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-06-20
MD5: 21b0b9766caeb61344aa31ebac111d56 SHA-1: c684f355c250fa246fc7ae5f08e4dc9c86d3a0c5 SHA-256: 513307acdc3194cc5fb26ef2e07c0b463704176f1e4447f6b23d6973a624f6d2
332 Risk Score

Malware Insights

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

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious File

The file is an Excel spreadsheet containing an embedded Equation Editor object, which is a known vector for exploiting CVE-2017-11882. This object contains a payload that, when triggered, leads to the execution of a secondary embedded PDF file. The PDF itself exhibits suspicious static findings, indicating it is likely a downloader or dropper for further malicious content. ClamAV detections confirm the malicious nature and identify it as a downloader.

Heuristics 9

  • 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.
  • x86 GetPC stub (CALL $+5; POP EBP) high SC_GETPC_CALL
    x86 GetPC stub (CALL $+5; POP EBP)
  • 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/xap/1.0/
    • http://ns.adobe.com/pdf/1.3/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/iX/1.0/
    • http://www.iec.ch

Extracted artifacts 7

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
48b29d88185d154e3ae741030a77651403a3f946f067d4ae7170904904d1c141		 ole-package OLE Ole10Native stream: MBD000E06D9/olE10nATIvE 1584 bytes
stream_005_off00021c15.bin
687dc13e09bd40942bfe2843bb5e4d3d7207221c46649b167abab388296f27c6		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x21C15 39292 bytes
icc_00_off00013f99.icc
2b3aa1645779a9e634744faf9b01e9102b0c9b88fd6deced7934df86b949af7e		 pdf-icc-profile PDF ICC profile at offset 0x13F99 3144 bytes
polyglot_child_pdf_off00008400.pdf
b37c4fbf8f703bfb375f7496d0963435e05e1b38db2e0149276126d2966ec9b4		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x8400 2065408 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0001dc00.pdf
268d45463fdcab032341e98cf997d7bf77762fe62d616ec2b631c17140d3f120		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1DC00 1977344 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off00099600.pdf
d45c2a659551bead48f59a22a06d0a16cd333771f1ed1df86006564f044aed5a		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x99600 1470976 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.