Malicious PDF — malware analysis report

Static analysis result for SHA-256 35237b3231cbb599…

MALICIOUS

PDF

77.8 KB Created: 2021-06-19 23:11:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 387e53211e8eca25406a928a071579f0 SHA-1: 20254409c1818b30b4c2300205c280fd2dd4d735 SHA-256: 35237b3231cbb599422a77542a8c35ea54a51c32f220c83a5c7c7016efcf68e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress upload storage, suggesting it functions as a link farm for phishing or malware distribution. The document body, though heavily obfuscated, appears to be a lure related to 'well tempered clavier bach pdf', likely to trick users into clicking the embedded malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://coretry.ru/uplcv?utm_term=well+tempered+clavier+bach+pdf PDF link annotation
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbf7496193f---nufuru.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8131646ec---7123200591.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/tuuchsqbpj47llllrkcn886j54/zoribaxujusoxupesibo.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/63776866819.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/2a384a052671f95d1d2c803bdd92be90/tisokosir.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160985470bbf97---vajanigepiwu.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/6d5118fe23a686293312158342d31a76/lexebamowapekapuni.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160afbf32bcc60---setibujosezirumibivokivab.pdfIn PDF document text
    • https://congchungnguyenlieu.com/uploads/files/palawajufu.pdfIn PDF document text
    • http://ihvanturizm.com/rsm/files/38685935911.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/fevafisenikezovi.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a7f942b5b60029efba6b264eaf84a27e/16305797665.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d11378dad5---6458739212.pdfIn PDF document text
    • https://psiakocky-potisk.cz/webpagebuilder/ckfinder/userfiles/files/votoluregabufazitaji.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9ac1df4f0---gusemitiwenufu.pdfIn PDF document text
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/mip2q39s6efoluf9dupkhls9un/70929682521.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e421.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE421 3068 bytes
SHA-256: 4a874eb1ba5c87732194c9a2b17b9f02cff39e82ccd3a2a7670b627809885069
font_01_sfnt_off0000ef0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF0E 5428 bytes
SHA-256: 491f8f19ecbd0447401c2122d86faf1a2eb70c7aab006a42b8ccd4df5a516cac
font_02_sfnt_off00010167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10167 12148 bytes
SHA-256: 0a160567c0b81b1f1a42ade1c0e394c4cd25ed1fb432a10c02e792cc7bff01bd