Malicious PDF — malware analysis report

Static analysis result for SHA-256 87ae4f7af84e4135…

MALICIOUS

PDF

84.0 KB Created: 2021-08-31 17:38:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9bbf2d57bac546a50988973ce996ef6f SHA-1: 496b63a74979f84d5ace3b34fade6fc164d9ff8f SHA-256: 87ae4f7af84e413543ae6c9b80b2d83a5b16752abad80b89ea15e4db0523b0f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains a link farm pointing to multiple PDF files hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The presence of external URIs and link farms indicates an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://mecaniquekd.ca/upload/file/zetikujudonone.pdf In PDF document text
    • http://lamachine.nl/userfiles/file/vazope.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/99082279946.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/5cf351c6ffd18ab69ef8d8fd10c0e547/58688437494.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/59d80e59dbd095edffcd7081aff66e41/67849918306.pdfIn PDF document text
    • http://stsaischoolamritsar.com/slbdavbatala/userfiles/file/vorafuxukalegobovurudozo.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/58254126634.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/9192922499.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8e702569a---dibejuv.pdfIn PDF document text
    • http://newshop.jp/archive/file/97138205351.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a15ebbe77b9---porixuresolitibinujupa.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/52040121606.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae43931ae42---81450323424.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/4c0ec5ce90cd0ea3be47561589bfd40a/79256698919.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a961dd58804---xaxewimo.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/e4eec379e862546d25d599cb5a3bbe32/zoxoxukamux.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/o99gn65lh7j3l3c55l2plis711/dedixukuxex.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/5b1153ae3a2668411b41e2b9bbd89bec/9837057993.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/e97b2da8364ae794d29a0f2ee36071c4/bezenojofu.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1610ca19f84470---rapubemigakologukena.pdfIn PDF document text
    • http://gugugroup.com/userfiles/wabezubureburoxusimi.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/3d8397fcfb2354ef8284d4747a36cc26/buvugeroxipu.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/9b37459c48f78a1f5aa7976f2e9084c2/18912003076.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072c7d2ef601---wuvatevobexabunubunojovif.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/okqugqvflf7t78eh341vjd2hnp/83575462074.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/vl8bh01jpf0ccfi8gpckfb3bh2/mitovelinojefez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=torque+wrench+specification+pdfPDF 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_off0000e14d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE14D 18420 bytes
SHA-256: 921d929abf1517d42e47fe23881887c724d7f77a24a7a06257c311ef0dbbb407
font_01_sfnt_off000110eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012902.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12902 10964 bytes
SHA-256: 29f309248ed4b2b338794ec8dd9cd25369e3f99537e78660167ac50bee29e6d5