Malicious PDF — malware analysis report

Static analysis result for SHA-256 61115f59ceb8f123…

MALICIOUS

PDF

87.4 KB Created: 2021-10-11 13:45:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: b4b79789a1aab5db627cae7c40d700b1 SHA-1: ef781c9daa5823d3dd6e914a704804fed7f8aa53 SHA-256: 61115f59ceb8f1236ce8034ff48df0f43c00ed584263172d270600837e32e5f0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://wamer.org/userfiles/file/mokijanaras.pdf In PDF document text
    • https://tckontrola.hr/files/50765095086.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/lamusitomuno.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/12075070761.pdfIn PDF document text
    • http://videotour24.com/data/fckupload/file/nadimajanamirerekife.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/52272864536.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210907171811.pdfIn PDF document text
    • http://tokyosushilohaus.com/uploads/files/sumidisisavatagivarazi.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/lk82s0ljkvio3tu9f3im1bb267/nopinisutijo.pdfIn PDF document text
    • http://arniuniversity.in/ci/userfiles/files/mulusafolatoxiwebigubud.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/murumorufobatuditineruwuj.pdfIn PDF document text
    • https://refakatci.net/userfiles/file/14571168801.pdfIn PDF document text
    • http://ecofincas.net/ckfinder/userfiles/files/95106973435.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/noguxazesalevesedanerur.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd150e568b---korojebamemajesal.pdfIn PDF document text
    • http://ternovykh.ru/content/file/54424850637.pdfIn PDF document text
    • http://struttur-arch.it/userfiles/files/55908073251.pdfIn PDF document text
    • https://magicdiscoradio.com/userfiles/file/48625162360.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/89083926375.pdfIn PDF document text
    • https://ceccarmehedinti.ro/userfiles/file/sokukiraxamoso.pdfIn PDF document text
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/86344385147.pdfIn PDF document text
    • https://infotechsystemsonline.com/ital/www/img/file/4570789698.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/4dZi1sgP-vI/uplcv?utm_term=team+accomplishments+examplesPDF 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_off0000ef26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF26 18760 bytes
SHA-256: f60c2cc25d93a2e1f6ce54ba5869c1f51da7210699f8871a11ae567e216c8cb4
font_01_sfnt_off00011fd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD0 10604 bytes
SHA-256: b1bf78332f4b38e5b03b34fff2afb94dcc4056b275cde128db1b49c3e6b640fb
font_02_sfnt_off000137dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1