Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1adf43905a3611b…

MALICIOUS

PDF

74.5 KB Created: 2021-09-08 21:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 92ab2c74912270fcfe8f4b6e73b7942e SHA-1: 0f0a64ab853aa2b6cb1285d4aaa60c2e32749932 SHA-256: d1adf43905a3611b1fbe88000ac90f90b75d127a50f821727356a0cb554544f1
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially malicious content. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool, suggesting it's not intended for direct user interaction but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.totspotdaynursery.co.uk/ckfinder/userfiles/files/88042022191.pdf In PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/ch0vesrnslfolo0qe1ak2jjs00/81644206620.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///54062433233.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/zabikidarajixobuwa.pdfIn PDF document text
    • https://ladymamashop.com/uploads/files/202109040701331193.pdfIn PDF document text
    • http://materialdeestudo.top/userfiles/files/55913359456.pdfIn PDF document text
    • https://ismet.com.br/ckfinder/userfiles/files/47628856999.pdfIn PDF document text
    • http://about-dogs.ru/upload/file/91096756548.pdfIn PDF document text
    • http://p-itos.net/admin/userfile/image/file/boxigomeve.pdfIn PDF document text
    • http://antonioruizabogados.es/userfiles/file/2425903396.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/12fad783e0096d460d2ed0c14e6349d5/medenajaxi.pdfIn PDF document text
    • http://gz-chengeng.com/uploadfile/files/liwame.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/zogipal.pdfIn PDF document text
    • http://gruaszarate.com/ckfinder/userfiles/files/vujezogemozitezupo.pdfIn PDF document text
    • http://xn--krmer-dnnebacke-1kb72b.de/files/file/41914792743.pdfIn PDF document text
    • http://www.vegagastro.pl/upload/file/60179678759.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/xumenowuzefub.pdfIn PDF document text
    • https://xnkvinatimex.com/uploads/files/wowaturuwagepuwegenifis.pdfIn PDF document text
    • http://vincentianssjp.com/userfiles/file/bivabubekefizenofimosural.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/96293942057.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/liwasugiwix.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/99004341040.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/suxaxoxekanorafumave.pdfIn PDF document text
    • http://islandpointfl.com/userimages/13754956276.pdfIn PDF document text
    • http://asavn.vn/uploads/userfiles/files/20822778302.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=diabetic+nephropathy+journal+pdfPDF 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_off0000c0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D0 16312 bytes
SHA-256: f17e57a0a38324bb110bb0ac7f55ee65a43b91e45ca4a2b94980e7a993a86832
font_02_sfnt_off000102bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102BC 11036 bytes
SHA-256: ec555695c3d713150815037b0dfb95137e3958bc9f8a9ca8abb0682d3e141d26