Malicious PDF — malware analysis report

Static analysis result for SHA-256 f13cf1f47a0130a2…

MALICIOUS

PDF

73.0 KB Created: 2021-09-16 12:51:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dfb7724438368c4c4afcbd2a71eb5521 SHA-1: 98f793dd6c92beb2bd24d637548e07e1fb8406ff SHA-256: f13cf1f47a0130a2ecd7fceacf3517a01f186562ae502296e144aeabf15c3acd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document's purpose is to act as a link farm, likely to distribute malware or conduct phishing attacks. The presence of external URIs and link farms suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://smidgel.ru/uplcv?utm_term=crafting+and+building+apk+1.17 PDF link annotation
    • http://vodova51-53.cz/files/78276100791.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/64564428150.pdfIn PDF document text
    • http://bandbaajabarat.com/ci/userfiles/files/78921061127.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/nisig.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9035519ff---zopoxowizunevo.pdfIn PDF document text
    • https://ezastupitelstvo.sk/editor_uploads/system/files/66890705884.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/2887373059.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7fb45db0b---61822426084.pdfIn PDF document text
    • http://alconsprom.ru/ckfinder/userfiles/files/11974658105.pdfIn PDF document text
    • http://fullerton.kopanramen.com/uploads/files/zimilato.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2e773933d---62318594811.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109140637048470.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/10043190402.pdfIn PDF document text
    • https://medpressa.ru/files/file/kituwoj.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/81048645350.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/t4etf0lrdpdqukk52dqbicijb1/xakutebafupajelotaz.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/rotuvaxopekavanejanul.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/ripaweruduziw.pdfIn PDF document text
    • https://daiichitravel.com/uploads/news_file/sipazafupu.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/55765220239.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/viropoponudis.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/4523904023.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/12653811493.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/wajefukimuxufikeberiso.pdfIn PDF document text
    • http://teplolux72.ru/upload/file/fovimul.pdfIn 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://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_off0000baa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d2b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2B9 10784 bytes
SHA-256: af51780732196859ffad2021383b1d427f975b71422e442da36db2f1d2f7d24e
font_02_sfnt_off0000eb43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB43 16696 bytes
SHA-256: 5b37c6c578f788b204bfa7b2190a2e2f7a2b74bfd4664344b89da5aab7321292