Malicious PDF — malware analysis report

Static analysis result for SHA-256 145fae7bc779a4a9…

MALICIOUS

PDF

75.5 KB Created: 2021-08-20 08:21:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8fc21ce7b1f29c6c352e45cda8133a5a SHA-1: 3f8e036b889faa6248c1a18582ed5a52cc46bb67 SHA-256: 145fae7bc779a4a98de9f4ee5679f877c4672d7d18f40749f8c7c4473d316d16
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various websites, many of which appear to be compromised CMS uploads. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it's designed as a link farm on disposable hosting. The primary purpose seems to be redirecting users to potentially harmful content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/r45u7mnae48o261emjfkpkddt9/dopuvunalaseviganoke.pdf In PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2e5de67df---vumofeditafip.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/69676949184.pdfIn PDF document text
    • http://beijinghuojia.cn/userfiles/file/koxogobilujanasutofegod.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/lezuwiviwakireremudozuje.pdfIn PDF document text
    • http://pi-consulting.ch/download/segemobobevemononujiv.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///21049061091.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210522125432_r86yy0.pdfIn PDF document text
    • http://lagunaapartman.hu/images/user/file/88532696944.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/jogefegofofu.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b8815092c---ramitebaxizibinagabezere.pdfIn PDF document text
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/d76317cb06d17438b6bdcc28d40410ef/7837624715.pdfIn PDF document text
    • https://kristinanamaste.eu/files/69667355053.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/3ihv7qdc5nnm21khjd5g32hrl7/26008890021.pdfIn PDF document text
    • http://etabetasurvey.com/userfiles/files/47877867407.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/merux.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/31531448424.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/64082829409.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/48809667422.pdfIn PDF document text
    • http://skylineidaho69.com/clients/c/c7/c7306e0a9cc1d421caefa9c307ca601f/File/fetageweson.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ca0km4ji0t3u9q3433ud9sr37j/tadozunokigon.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/55033775091.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ed1f04f1f56---vebapemotixosuxawa.pdfIn PDF document text
    • https://cecprint.com/images/file/67229852415.pdfIn PDF document text
    • https://orsam.org.tr/paketler/ckfinder/dosyalar/files/zazedeze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=10.s%C4%B1n%C4%B1f+fizik+1.%C3%BCnite+ders+notlar%C4%B1+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_off0000c0a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B8 11024 bytes
SHA-256: d66b0a4b7b7de454a3778227530e1460650c734b24bf94e9477803fb6c14f416
font_02_sfnt_off0000f256.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF256 17872 bytes
SHA-256: b5b3338ec7d40def349261fee40554be7e053de3380a899c82b7e56a8083eab8