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

Static analysis result for SHA-256 1ff6beb38f778457…

MALICIOUS

Office (OLE) / .XLS

1.02 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-07-14
MD5: 625ee5fad86d0c6d64a92b2e3ccf7d21 SHA-1: 9d70c769490b5c2a0cae13ac56223945fcf72c35 SHA-256: 1ff6beb38f7784578786d80f4665580b7fd6f4dc79240b6ae4bd409f283ebb92
384 Risk Score

Malware Insights

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

MITRE ATT&CK
T1204 Malicious File T1566 Phishing T1204.002 Malicious File: User Execution T1059 Command and Scripting Interpreter

The XLS file contains an embedded Equation Editor object that exploits CVE-2017-11882. This object is designed to deliver a secondary PDF payload, which in turn contains a direct link to a payload. The ClamAV detection name 'Xls.Downloader.94c25b356b5a6cac-9978798-0' further supports its role 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.
  • 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
  • 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.
  • 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.
  • 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
ole10native_00.bin
1eb14a922189d988a7ee2b250005c88f3d5efd7c2c467e7bc5b9ec314654076f		 ole-package OLE Ole10Native stream: MBD001193E9/OLE10natIve 1796 bytes
font_00_sfnt_off00007f7d.bin
68d167e68895a344f3603a4efd0d8438eb8fdebe759cee48f2b4adf75c76c961		 pdf-font-stream PDF embedded font (sfnt) at offset 0x7F7D 12100 bytes
font_01_sfnt_off00009d95.bin
50551000b9f90b3f445ee94749557d9ddf96697a74984b3ccf3d2bae66910750		 pdf-font-stream PDF embedded font (sfnt) at offset 0x9D95 15820 bytes
polyglot_child_pdf_off00001000.pdf
3dca947f2828edc4679db9ac5b2b1bd47604133018359e4d7deaaee44749f217		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1000 1066496 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off00006000.pdf
7bd12eeb216624439b26a442ae7dcee1e3f4e2e3002c98e8f3bcddbc1c8726cc		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6000 1046016 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0000e400.pdf
d6b225e82df15d675c065f7627c419813fbdae4c7f0c356cd3981f72fc4f0f00		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0xE400 1012224 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely
polyglot_child_pdf_off0002d000.pdf
bd5821c3d6a459bfdfbeecd1f1069120b53ec33ac217fa5fcb3919346b9c6af7		 polyglot-child-pdf Secondary PDF body inside ole container at offset 0x2D000 886272 bytes
Detection
ClamAV: Xls.Downloader.94c25b356b5a6cac-9978798-0
Obfuscation or payload: unlikely

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