Malicious PDF — malware analysis report

Static analysis result for SHA-256 531c8ac3808f26f4…

MALICIOUS

PDF

87.3 KB Created: 2021-07-18 15:32:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1733ef71a5d8f86dc9e9a0bd4b3088e2 SHA-1: d7bce4607306814b06daf3038e7c5aa37503c46b SHA-256: 531c8ac3808f26f4165261e4f218e0929b0775db47b66ac8b7eb0827155baaf8
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a link farm pointing to compromised WordPress sites and disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving exploitation for client execution via the embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://on-video.com/movies/movie_data/file/56791038324.pdf In PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/615260a3b654fbaa56533004f24cbb98/rijawabigelododewog.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/bce49d76baf6c46d2f49a13a3ff89f2d/wuruvusipalogezitidirizu.pdfIn PDF document text
    • http://scarpatti.com/files/madujobagivajixanobabifu.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/wototofunogenerame.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/bqfkc2n0ot5m07792hqqu6054a/40280074857.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b8b608237---kepiruwomikivuketujij.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/kfevgp6cea9dsen6op8gk7omea/21919944498.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/1560571ef346143b0d0b4c2c40c6b25d/16366540597.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/70647657661.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b258649efd8---39461687892.pdfIn PDF document text
    • https://registracijakoncar.com/webroot/js/ckfinder/userfiles/files/zokasowatefaw.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/padowejezowiborixibubalap.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a02cf71f23241ac7a8e527f8c7f813aa/81044317106.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/64aga5rqg8pk69etbuekkrmkn1/favajimur.pdfIn PDF document text
    • http://www.toptehnik.si/images/34304449305.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc67385379---zexikosinifimob.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe2091b654---zijab.pdfIn PDF document text
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/505fec8085c235e8a0953c133040a1d6/bolavugonutovelizevukomok.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/dimapaga.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e33fc243c1---tizevizevedu.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/23920fb318825425ceaed402c94baff0/52274617715.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0682ab3aef---97219286758.pdfIn PDF document text
    • http://schokobrunnen.com/idata/rimefokiwikoxamag.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/28247957938.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=things+that+rhyme+with+nationPDF 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_off0000f265.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF265 10672 bytes
SHA-256: bc38db65ec2c00550ec75ce6c2afe4742e99381fad9bf611e5f8f23516689474
font_01_sfnt_off00010ac3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC3 17236 bytes
SHA-256: 549aaf8a24e3d76f8f79ec3d2995c89294c36b15b232c728eeef48241c041238
font_02_sfnt_off000137ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1