Malicious PDF — malware analysis report

Static analysis result for SHA-256 c42d0e66028e6f61…

MALICIOUS

PDF

75.2 KB Created: 2021-09-12 20:12:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bfc37fefbc578ba2d392fe19ee374160 SHA-1: 7b33300d86dda384026812317efc172da85c9f33 SHA-256: c42d0e66028e6f6197e5e3fb17d3a5b5ade837e8dba334d608a3c93fe7285d67
126 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs pointing to PDF files hosted on various domains, suggesting a link farm or distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://rosettes.it/userfiles/file/pipuverikunubakuvaxi.pdf In PDF document text
    • http://sujitonweb.com/userfiles/files/kipalaramopozizifuli.pdfIn PDF document text
    • http://espokebar.com/uploads/files/23474906230.pdfIn PDF document text
    • http://juncheng.tw/upload/files/33758149089.pdfIn PDF document text
    • http://sp2wronki.pl/fotki/fotki/file/kirofeto.pdfIn PDF document text
    • http://brava-ekb.ru/userfiles/file/51041672235.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16137d7ffc83e8---poguxola.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/98978433006.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/kidagi.pdfIn PDF document text
    • http://lrm.mcdonalds.ua/ckfinder/userfiles/files/37544114904.pdfIn PDF document text
    • https://songod.vn/uploads/image/files/39392902364.pdfIn PDF document text
    • https://amigo-shop.105h.net/upload/files/gaxupotomepufegu.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/vamudut.pdfIn PDF document text
    • http://laser-piskovani.cz/democms/userfiles/file/gelidabapob.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/91083461820.pdfIn PDF document text
    • http://spy-military-labs.com/userfiles/file/fokukejobudotomokumi.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/ntn2g1s2d855p4ihbef8pu5f87/30782675684.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090800040171333.pdfIn PDF document text
    • https://kozlovka.mebel18.com/uploads/files/9014350054.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/85959449642.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/vomafebomelamelelemigo.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/jifunikonobowafomepuvu.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/45932692383.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210909120458.pdfIn PDF document text
    • http://soft-pro.hr/upload/datoteke/60761743113.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=avg+secure+vpn+mod+apkPDF 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_off0000bf97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF97 17800 bytes
SHA-256: 2e56840775e9787ca33df59c241fad9eca403dd667275a0c8869f4320f6912e6
font_01_sfnt_off0000edc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC7 10860 bytes
SHA-256: 3d3b9e258c5ec79d58c7ff3ed061533d395374ab45306efb6f7f4e1af25bb218
font_02_sfnt_off000106ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1