Malicious PDF — malware analysis report

Static analysis result for SHA-256 11b4039e0f61591a…

MALICIOUS

PDF

84.4 KB Created: 2021-09-17 09:30:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 83e751cd097ebc335a35ddead1492eef SHA-1: 7ae490cee48b5e78b778f9fd32c4423d00473a64 SHA-256: 11b4039e0f61591a61738ffa4346e2a32057feb595c32c62cf05b196a92b1e1c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document functions as a link farm, likely for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://archetipoingegneria.it/userfiles/files/gaxovizudopuzomalagolaw.pdf In PDF document text
    • http://hairfibers24.com/upload/file/gapegamuwuva.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139d1d6d01ac---xuvibebuvolexo.pdfIn PDF document text
    • http://avandcie-automation.com/ckfinder/userfiles/files/lugumosaz.pdfIn PDF document text
    • http://plechotice.sk/tmp/file/43615901905.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/61290399591.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/rapepi.pdfIn PDF document text
    • http://i-dron.cz/data/file/rovotaluzezavigezam.pdfIn PDF document text
    • http://kingswaytyres.com/project/kingsway/uploads/file/50736431914.pdfIn PDF document text
    • http://orvositudasbazis.eu/images/upload/file/muradikemafuvadix.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16141ed311cecd---fexixugesogojemimebe.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/10396485256135e653c9fff.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/33756486636.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/kalegemivoribavin.pdfIn PDF document text
    • http://lrm.mcdonalds.ua/ckfinder/userfiles/files/57092391694.pdfIn PDF document text
    • http://osteriailgalloelinnamorata.com/userfiles/files/5213649819.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/163073596915a2c2fe6d12bdc21e16.pdfIn PDF document text
    • http://cascad-trans.ru/files/jaxojanokojomir.pdfIn PDF document text
    • http://isotope3.pm-ural.com/uploads/files/pinatikoguwilenudagurife.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/eb2c0d8dae56edf9dcd7cd78be5cea94/16350625489.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=siren+head+game+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE903 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10115 17172 bytes
SHA-256: e4866f0e071e3c2ca535c73f04ac948b5f59f6c1e2e2c872e358bfc1767070d2
font_02_sfnt_off00012d63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D63 10456 bytes
SHA-256: 3f163cd1b356ed1f2c91d7eb68b1affd2fde7d055519275ecf275876ca5eb5a2