Malicious PDF — malware analysis report

Static analysis result for SHA-256 91254c30d02fe17e…

MALICIOUS

PDF

87.8 KB Created: 2021-09-02 10:25:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5046aac14fc982742871f45ae421062b SHA-1: 9dad6b387d5398c2f0a58181f6d1d14b012bc941 SHA-256: 91254c30d02fe17e248a3aab5c0eac791054902b337b7b488e329e1729735af2
104 Risk Score

Malware Insights

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

The sample was identified as malicious by an ML classifier and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to other PDF files, many hosted on compromised CMS uploads or disposable domains. The presence of urgency lures suggests an attempt to prompt immediate user interaction with these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 6

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://whatdwellswithin.com/file/rokazi.pdf In PDF document text
    • http://akinmedical.com/uploads/file/93621995946.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c775259c90a---jofawetudegavitefidoganim.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce100b8810---69405171077.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/91906176399.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/30284340250.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/visamisozotuvetunozugamu.pdfIn PDF document text
    • https://ngonluathan.com/images/ckeditor/files/8845299664.pdfIn PDF document text
    • http://xn--l3cbpp3gh4a5g5c.com/userfiles/files/gapibuzo.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160cc89378bc27---muketokoxakaworibol.pdfIn PDF document text
    • http://erictex.com/ufiles/files/sevonusefinadeli.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/giwebotefugekeg.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/ardtfmsn6jajk13qaek1kiaqis/ketenedudubavita.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/95502494692.pdfIn PDF document text
    • http://galluccifaibano.it/userfiles/file/12693120281.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/662f10cf3c134b3ae5a1a1fed39b089e/litezigibavunibalisojuz.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/9136a334156190329db5b2e59a023454/wojova.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210830_2E1242FDD98A0876.pdfIn PDF document text
    • http://arebiatours.com/uploads/files/92706179183.pdfIn PDF document text
    • http://sushiloverca.com/uploads/files/kesur.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/sivafalutixumepozami.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a458a869638---5671506690.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160719d7a8905e---78482008240.pdfIn PDF document text
    • https://agermag.ro/mm/file/27242417928.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/cf55cfb51a0e46cde4e90d72a9315b7e/bapefuzuzuzu.pdfIn PDF document text
    • http://www.nagsa.es/ckfinder/userfiles/files/698471518.pdfIn PDF document text
    • http://promador.pl/userfiles/file/9956356615.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=chapter+2+english+class+10+questions+and+answersPDF 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_off0000efd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD6 11448 bytes
SHA-256: 028e1432ce47a9549c83e20053bff154e27750d2a897d9c68298e9021949e7e5
font_01_sfnt_off00010a7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001228c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228C 17872 bytes
SHA-256: d605d38cc4cebc91419a399523c061d4ac7ee67b57cada91e91288d3f7c3be91