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

Static analysis result for SHA-256 cec6fd426026dff8…

MALICIOUS

Office (OLE) / .XLS

1.25 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-09-21
MD5: b78294db2c83644d5ee898fe4ece75ba SHA-1: bfbd8cc767389ea193301bf2ac953f70f728216b SHA-256: cec6fd426026dff8d32697bbc8d2de48b4df6d80127fe1cf9e9e89fa61f07097
272 Risk Score

Malware Insights

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

The sample is an Excel file containing an embedded Equation Editor object that exploits CVE-2017-11882. This object contains a secondary PDF payload which, in turn, contains a direct link to an executable payload. The VBA macros are present but contain no executable statements, indicating they are not the primary infection vector. The primary attack vector appears to be the exploitation of the Equation Editor vulnerability to deliver a malicious PDF.

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.
  • 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.
  • 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
c10a0be3fd5f119d830b5fcc501442292369d865df409448b6cfdca09e9036d0
ole-package OLE Ole10Native stream: MBD00041471/oLe10NaTivE 1696 bytes
polyglot_child_pdf_off00060c00.pdf
a758513dc677d0580b0ff11642fb07e39f717ce44bd684c8b1920d7d937f1eed
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x60C00 911872 bytes
stream_003_off00005f60.bin
2998a126f4fa11ceb265371a5f7968ec18bc4692a32631a544232dc74040021f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5F60 252488 bytes
polyglot_child_pdf_off00001000.pdf
511a9e39fe3e73b77aa4ebfd5456aa928a1da0e7c5711c168d53c11a0d3f7733
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1000 1304064 bytes
polyglot_child_pdf_off00006600.pdf
c4a5f17bed761139d55795478a794b3628bf6467e080f06a5f3812a028d045b5
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6600 1282048 bytes
polyglot_child_pdf_off00029600.pdf
a72913043e8596e9b396f2db4e2a425feaf0d6d6945b92a575af31d80ac0fc5a
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x29600 1138688 bytes