Malicious PDF — malware analysis report

Static analysis result for SHA-256 81dbca5c427b577f…

MALICIOUS

PDF

86.3 KB Created: 2021-08-13 03:24:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 78221b87c141a35a7af8fc725d306a49 SHA-1: b5c71af8158c68cbdf44ad771c3c9368478b20ed SHA-256: 81dbca5c427b577ffca66da58d7941199083fd645925caf5f96557bc39cd3f0e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites, which in turn host other PDFs. This structure suggests a link farm designed to distribute malicious content, likely for phishing or malware delivery. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d16285c95---3511348923.pdf In PDF document text
    • http://maraulsan.com/ckfinder/userfiles/files/govesasovitowezutafi.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/681e06b21cad0bc6e28abb626fbf89dc/66770576407.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b03af19890---25705468762.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/4e0341e7c6d00c3bd3c7c8a8db607931/95276893788.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/fizofifusegekixujuniwax.pdfIn PDF document text
    • http://geologocarmignani.com/userfiles/files/24127413842.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/bulevevo.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/pquhl21q5mkhbe8e4ec4o6dtf8/foxutakudori.pdfIn PDF document text
    • https://juniorclublivorno.com/sitonews/images_upload/files/suzezi.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/4d4c38e81097a68fb091ee64f77cfbdc/98329836668.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/93987242138.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/rp89ajfg2sr8o3sc66bdk0ris5/96440067561.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/raxejirajenebuwolijew.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/2412881050.pdfIn PDF document text
    • http://teechart.com/uploads/images/files/mozoxifekemezus.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8c3a277b3d---89406796426.pdfIn PDF document text
    • http://activesolutionelectric.com/images/file/3946840810.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3266e2ac94---rexodepigozak.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9a6b3028d---43626572966.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=unnai+pol+oruvan+full+movie+download+single+partPDF 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_off0000edfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10611 11100 bytes
SHA-256: bae1f73d38ae632a9aca2f7aac30e02a1eb1d0ad4b31a21c5e733f8534a26ea3
font_02_sfnt_off00011fc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC7 16616 bytes
SHA-256: 611cfa5626a61552be67c5c7d0dd63d5101146e12889ef4d733774178db281e7