Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cbf436fbabd9fe1…

MALICIOUS

PDF

84.3 KB Created: 2021-07-09 17:18:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d879dec9e1cce3bbcdec2adcd9613bd8 SHA-1: 41f30ebaf0ebd1a50a3457e3b5b644ef2dfb8551 SHA-256: 7cbf436fbabd9fe1ff99e14503e40a9959be72a82818325269872a877322ddff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics point towards the document serving as a lure to malicious content, likely involving JavaScript execution within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://ketchas.ru/uplcv?utm_term=adverse+effect+of+dehydration
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/f2053fad91fac7d0d6c4a2700cea7e26/38429672779.pdf
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/e15a448b2cbaea114611f475d4d0f04b/beluvajorezuv.pdf
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/a45f4a0e57abe05a458ecb08e9a2a49d/75063186697.pdf
    • http://autoscuolecasetta.it/userfiles/files/82514006297.pdf
    • http://dnepropress.net/files/file/zubix.pdf
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/11344241798.pdf
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/mumavinifivolefeza.pdf
    • http://casaatlantida.com/userfiles/file///17055836926.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb4bb5a579---30418664456.pdf
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607e80d64786b---69133358465.pdf
    • https://home-consult.lu/userfiles/files/27861055857.pdf
    • http://hibertek.com/image/files/20210618_011320.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077eb43a8a62---dunuxapebe.pdf
    • http://cdhsalumni.com/clients/28864/File/83028939143.pdf
    • https://2-view.org/home/view/public_html/ckfinder/userfiles/files/gugukiraputilawu.pdf
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e39ba87180b---zazamoxumuduxotejemej.pdf
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a708fb0c4be---18949657472.pdf
    • http://epoetryworld.com/clients/53741/File/guwuwutijusu.pdf
    • http://abaj.cz/UserFiles/File/vupanalif.pdf
    • http://mobydick-band.de/fckdata/file/75238135255.pdf
    • http://sequirk.ie/userfiles/file/buvatigulujepepiligebukeg.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e94d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE94D 16792 bytes
font_01_sfnt_off00010164.bin
892dc107f32cbe447b4fca2c0db603e9bd77a83b1d9b350daebee057821dfa99
pdf-font-stream PDF embedded font (sfnt) at offset 0x10164 10688 bytes
font_02_sfnt_off000119ec.bin
b38224a358d9485b828a3b1298e74c8786aac3eec9feeed2b543eb97829c225c
pdf-font-stream PDF embedded font (sfnt) at offset 0x119EC 16296 bytes