Malicious PDF — malware analysis report

Static analysis result for SHA-256 763e04fa18e7b83f…

MALICIOUS

PDF

137.8 KB Created: 2021-06-10 23:22:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 8929f3425d1e23311db3e15404fbf44f SHA-1: 2ca2b1e22ff3151fcb5f3eac4d57e579eac49a41 SHA-256: 763e04fa18e7b83f687f910ea5d29dea5a87b68c49026eb7030b993f4a9b3eb8
156 Risk Score

Malware Insights

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

This PDF file contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging JavaScript for exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://cructi.ru/uplcv?utm_term=fundamentals+of+thermodynamics+van+wylen+pdf PDF link annotation
    • https://earplighting.com/wp-content/plugins/super-forms/uploads/php/files/acb84c2cc041875db3b6e62f7b105d5d/66676703159.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/d89517bf4d40ebe3af089f44c1aa413c/purufasuvinetawuvisiwosix.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/53306078908.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/644984d3833fc979dcc42b7af7b859ff/44868661631.pdfIn PDF document text
    • http://10glazsikeyrosa.ru/file/minux.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072e9b7ddedd---ninabowuganofudivevuz.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160784a32cd652---22338701331.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/b313cd24fa2ba45b492d40565ec9280b/81127172322.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/c7k4pinavlm2kksi8egu4r8b82/72450620338.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/dfddc827a065b606bd5a03b956b7d528/mazekifataxuvedajidelo.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/4557d13b7dcb2f76158c8c81a870a9b5/tajaso.pdfIn PDF document text
    • http://hcvitamin.com/webroot/img/files/tironalilo.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/59789059716.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001bc90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BC90 5604 bytes
SHA-256: bb9ce9f625606284ac3827cdbfe370e3147dc08f1a15fe340115604a7280e20e
font_01_sfnt_off0001cf8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CF8E 2256 bytes
SHA-256: f338b2cb763a4327ca34f97e5deef872aa0d75ed3ade001533242884dc238c61
font_02_sfnt_off0001d91e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D91E 12504 bytes
SHA-256: 2024b9ab0a032396582ea2464d390e514b3efcb5a4c3e395bc284e43594720e9
font_03_sfnt_off000203dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x203DD 16232 bytes
SHA-256: 3e1a24d0508365dcdef9e1e0067804635d6a0fe30a1e1cdb57038c408569073b