Malicious PDF — malware analysis report

Static analysis result for SHA-256 15df9838537866ab…

MALICIOUS

PDF

80.1 KB Created: 2021-09-08 16:30:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e2f95a5f2293e03d333f9e18a13a8621 SHA-1: 671084c26c1abe4a9ebf642eec588d5689f2ae79 SHA-256: 15df9838537866ab6ab51477efd9b43381dbc031726cabbc8f061ce804aaa56c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or appear to be compromised uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://krisoc.ru/uplcv?utm_term=limits+worksheet+%235 PDF link annotation
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/92447036025.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/31784499192.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/xofudifokojiludokola.pdfIn PDF document text
    • https://kiaavcilar.com/upload/ckfinder/files/jinaraduxupimamoxudaroru.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/goxujexubadipizojewo.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161335be7da8d5---lafewisi.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/71055418536.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/22249189939.pdfIn PDF document text
    • http://ekonopuntos.com/campannas/file/jusexokimaxulajivisapuref.pdfIn PDF document text
    • https://dalilak1.com/userfiles/file/busexixowotilibu.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/nasetenuxi.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/24416807580.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/fajir.pdfIn PDF document text
    • https://markaoyun.com/calisma2/files/uploads/71682417012.pdfIn PDF document text
    • http://recuva.kr/upload/fck_img/1631059819/file/zetimatebewita.pdfIn PDF document text
    • http://guitarenko.fr/img/files/90405918134.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/53422516017.pdfIn PDF document text
    • http://tl-maskinfabrik.dk/userfiles/file/gosemavakelufi.pdfIn PDF document text
    • http://studiorestagno.eu/userfiles/files/pelokotu.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/hmpcvbmcahfs976vgkc56t41b4/winogugusinuvilumu.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133f7ae19bc3---8401692530.pdfIn PDF document text
    • http://jpsacademy.com/slbdavbatala/userfiles/file/takuvuzawusenixadajumeki.pdfIn PDF document text
    • http://burmeseburmilla-allevamento.com/userfiles/files/71039407663.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/89301511535.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613826d050d51---47366287657.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_off0000d877.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD877 16892 bytes
SHA-256: d2f32f0b52ecbb927ce017c7a809729f13d67099c1ccdc003b79a9cf963403e0
font_01_sfnt_off00010424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10424 10196 bytes
SHA-256: 577cb3e5044fad531191e220f0ab5381e6080f41b57e1a696ec4f7454c2b65c9
font_02_sfnt_off00011b15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1