Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4430d52168cfe9a…

MALICIOUS

PDF

80.3 KB Created: 2021-09-23 05:30:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 44e8ac6acc132f19bd0f3a2f1c38f6dd SHA-1: 8ee10b12831df1749112422baf314108543e4bdc SHA-256: b4430d52168cfe9ad05ba9d6864ed86a5bdfe455da39a14b6f52990107c0307d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, suggesting a phishing or malware distribution campaign. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF's purpose is to redirect users to a large number of external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://crewmak.ru/uplcv?utm_term=area+of+a+sector+formula+degrees PDF link annotation
    • http://belly.bpv.su/content/files/files/sifazefem.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16143a2f88ec5c---nododavumelukutizi.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/70091689421.pdfIn PDF document text
    • http://sbkf.org/files/files/55160337016.pdfIn PDF document text
    • http://cuuhoatudong.com/upload/files/zedoxejifunebezevikerali.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/42093777256.pdfIn PDF document text
    • https://kirbas.com/img/uploaded/file/pabiganabamidosalufesakob.pdfIn PDF document text
    • http://gazduire-domeniu.com/UserFiles/file/52187904464.pdfIn PDF document text
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/wexovarevilejez.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109202232381385.pdfIn PDF document text
    • http://globomax.eu/userfiles/file/63645111378.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/26ujvmje1ku7mevpdd6i0d513t/numefimif.pdfIn PDF document text
    • https://milosislandrooms.gr/userfiles/file/xokedogizonozozalor.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/latizijasesagumubudovub.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/sabenozena.pdfIn PDF document text
    • http://rezidencianestor.sk/app/webroot/files/ckeditor/files/wugamewipojupuvewuzoki.pdfIn PDF document text
    • http://splogservice.ru/content/files/nejasibip.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/xorixonemuwasupame.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/51048626472.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/80015779.pdfIn PDF document text
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/41055143305.pdfIn PDF document text
    • http://dunakeszi.varosom.hu/userfiles/files/pimomusegapepumozetoz.pdfIn PDF document text
    • https://lochoanggia.com/upload/files/turowijelik.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16142152036c26---sikigukokuvemelija.pdfIn PDF document text
    • http://3e3i.com/UserFiles/file///43031035474.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_off0000d12d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD12D 10704 bytes
SHA-256: c866cbe5220277876e672bd6d35ff6fc0d23d5c10ffbc6085306fbe4d034189d
font_01_sfnt_off0000e9a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000101b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B5 19228 bytes
SHA-256: 0e3973051ad3f0440ffff00d0124c70b30fb0fd9b6ccc0a69cd0517342d36e63