Malicious PDF — malware analysis report

Static analysis result for SHA-256 b428bd77f51f7509…

MALICIOUS

PDF

75.9 KB Created: 2021-09-06 08:52:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5f4e1f3cb5beaee856f13a5edf1ef6a9 SHA-1: 050ed16d4f64f0944ddd02571ca1e3d6708cb1c7 SHA-256: b428bd77f51f7509bc2a1f1b5d43b69061a1e1b24f234b58322ad58f4a7c2203
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which appear to be hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest the document's purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://adamlegal.com/userfiles/file/3958667600.pdf In PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160ad97893c4d0---gigafuxivufex.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/74702654094.pdfIn PDF document text
    • http://wjcopy.com/upload/files/dimelepubupisimal.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d614e8e7e3---7698583505.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/84103179833.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5683db3ba7---27125855878.pdfIn PDF document text
    • http://vividconcept.in/userfiles/file/jurenotubaj.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/e09511e358783f85a65d1493a77b75c5/kapusoguvejur.pdfIn PDF document text
    • http://nextgt.eu/uploads/file/nadagesimojevatefisume.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e375ea944---70262196995.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/dogagobizefad.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/918c424c495240ed8a448d6a9e3d149a/653785082.pdfIn PDF document text
    • http://hawks79.com/clients/85064/File/92886687314.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/7600055643.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/20100040501.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16102845733326---pipabelexowi.pdfIn PDF document text
    • http://carsonpokebar.com/uploads/files/60628288429.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/30eaaae46e430f8d96c7ed0cb6537273/74812970893.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607797c8a1f9b---85047000371.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/56866574003.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/pezukepoxofesil.pdfIn PDF document text
    • http://fewo-spreewald-schoetzigk.de/brandenburgtag/img/editor/file/gijakidusigiwodepa.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4c889412ee---87733030440.pdfIn PDF document text
    • http://hebakotb.net/userfiles/file/62892318905.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=vocabulary+test+intermediate+level+pdfPDF 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_off0000c365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC365 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB7C 11168 bytes
SHA-256: 148290bdd89c92787249d8aeab2ebf0bcc96dd7506ccf62e41a46ce8cc94d8c2
font_02_sfnt_off0000f567.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF567 17404 bytes
SHA-256: 762052ed3074747d45d2045617b5d526ae946725b226b8dceacbe7ab21156f7f