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

Static analysis result for SHA-256 e743cf899576503e…

MALICIOUS

Office (OLE) / .XLS

1.38 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-10-03
MD5: 19202ef8b0f4d1536e4bf40e0246a2ec SHA-1: 1e570dea25b0f41bddf2d3e4b5fa887cc6f08a0e SHA-256: e743cf899576503ecd96fdd01f5f8b6775a681e6eaff832b602ea04872fe1e4a
372 Risk Score

Malware Insights

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

MITRE ATT&CK
T1204.002 User Execution: Malicious File T1566.001 Phishing: Spearphishing Attachment T1204 User Execution T1059.005 Command and Scripting Interpreter: Visual Basic

The file is an Excel spreadsheet containing an embedded Equation Editor object that exploits CVE-2017-11882. This object contains a secondary PDF payload which, in turn, has a direct link to an executable or archive. The VBA macros are present but do not contain executable statements, suggesting the primary malicious functionality is within the OLE object and the embedded PDF. The ClamAV detection name 'Xls.Downloader.94c25b356b5a6cac-9978798-0' further supports its role as a downloader.

Heuristics 10

  • 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
  • x86 GetPC stub (CALL $+5; POP ECX) high SC_GETPC_CALL
    x86 GetPC stub (CALL $+5; POP ECX)
  • 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.
  • 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
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

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
820f24816fcf34e28abfcf7cbd454d0bc9d23675f38a49604c978facae45e91e		 ole-package OLE Ole10Native stream: MBD002E5FC8/oLE10NAtive 1363 bytes
polyglot_child_pdf_off0006f800.pdf
024d15606d325e6d7da9beb3a070eb706e6c51d767d0a5b4def4a8773fa9815c		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6F800 986624 bytes
stream_004_off00005f60.bin
2998a126f4fa11ceb265371a5f7968ec18bc4692a32631a544232dc74040021f		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5F60 252488 bytes
polyglot_child_pdf_off00001000.pdf
c721ffc75bee621207589f448c9219f6529a1a4f6647ebb4eff3f9e11316e7a7		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1000 1439232 bytes
polyglot_child_pdf_off00006600.pdf
adb9ebeb765b0fe58393c81157a31b8319082da05d2b478b358d0a9718397c21		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6600 1417216 bytes
polyglot_child_pdf_off00029600.pdf
95c6af260a077d7b4ed59558ccd91d0a943b39fa854b4991f917ee469426602c		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x29600 1273856 bytes

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