Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc836e52a976186d…

MALICIOUS

PDF

75.6 KB Created: 2021-09-22 22:59:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 251cbf3b3fea703403d388f71c6f6b7c SHA-1: 801f82a8800b08f914012702ae1e2ec906b966e1 SHA-256: bc836e52a976186d3d657ecf240764be3d71b0bf97fd566394a0122e3df24b15
126 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The file functions as a link farm, containing numerous embedded URLs pointing to other PDF files hosted on various domains. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a pattern of using disposable hosting for these links, which is common in phishing and malware distribution schemes. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://ovstav.cz/app/webroot/files/files/gejexekozuvemef.pdf In PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/bufomutibofagafazij.pdfIn PDF document text
    • https://i-intelli.com/ckfinder/userfiles/files/88544140681.pdfIn PDF document text
    • http://volkshilfe-vlbg.at/images/content/files/nipoxuso.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/borugarekalulosutisonu.pdfIn PDF document text
    • http://cycling-software.com/files/file/digat.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/remanabuborek.pdfIn PDF document text
    • http://esipro.lu/userfiles/file/13958074848.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/a40e0bb7bf60a539d70bbd170ffea17a/30090517674.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/b9c0b06cc0e776bbc562a8826f5480c2/32717901154.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210921012521.pdfIn PDF document text
    • http://shinhwajudan.com/userData/board/file/rigubipaferataxinu.pdfIn PDF document text
    • http://maternites-catholiques.org/ressource/site-image/files/segolumituf.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/64250985582.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/11530247718.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/4623865712.pdfIn PDF document text
    • https://valve-toho.com/userfiles/file/pojagupanedadufidinasited.pdfIn PDF document text
    • https://svenjakretschmer.com/ckfinder/userfiles/files/sawaxaxevevuleda.pdfIn PDF document text
    • http://vevo.keresztessyoptika.hu/elemek/file/93063126623.pdfIn PDF document text
    • http://emannsltd.com/userfiles/53943726799.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/18902904914.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/jodiredikefote.pdfIn PDF document text
    • http://lifeisartfoundation.org/sites/default/files/images/userfiles/file/82591926216.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/natezaz.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/68544833711.pdfIn PDF document text
    • https://buzascsaba.hu/userFiles/file/3542090152.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=fishing+gif+funnyPDF 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_off0000c752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC752 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF64 16808 bytes
SHA-256: d944c394226092d989397d855664eed19d936054f01d7ac212c6bb79403302ac
font_02_sfnt_off00010a84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A84 10024 bytes
SHA-256: 14c96ff4f4c2a3021410e413b620a7b3f16db61e855ad4ec9afce37279995dc2