Malicious PDF — malware analysis report

Static analysis result for SHA-256 e16fcbd0993ce480…

MALICIOUS

PDF

81.1 KB Created: 2021-09-20 11:36:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7f7688f057b531b0222b26f317f8219d SHA-1: ecb8cbe30f490ae1bd6fb4b15cdb435419e147ef SHA-256: e16fcbd0993ce4803316b617968e8fd317ab85579edc1c904d0845086923e362
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised WordPress uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://veterina-naslunci.cz/userfiles/file/58070060239.pdf In PDF document text
    • http://logisticsnetworks.net/ckfinder/userfiles/files/61551730703.pdfIn PDF document text
    • http://minhquoc.vn/ckfinder/userfiles/files/74578625047.pdfIn PDF document text
    • http://szkolaprzybranowo.pl/ckfinder/userfiles/files/17955898896.pdfIn PDF document text
    • http://yilip.net/userData/board/file/73815423099.pdfIn PDF document text
    • http://rc-mst.com/mst/_upload/files/85852239253.pdfIn PDF document text
    • https://pamukoglu.com/userfiles/file/2165432237.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/58432437625.pdfIn PDF document text
    • http://wadsoda.com/UserFiles/File/mumoluwopanobaze.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/zakejenonijipitipu.pdfIn PDF document text
    • http://tuderprogettazione.it/userfiles/files/vetoxunexowej.pdfIn PDF document text
    • https://ryokanclub.com/FileData/ckfinder/files/20210918_64113DA06FF1F10A.pdfIn PDF document text
    • http://pn-tech.net/userData/board/file/35734321528.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/fasikaro.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210905164604.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/e8b75f32f9a3ad76de28433a80adb19f/7829823732.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/65919418157.pdfIn PDF document text
    • http://recrute.fr/files/files/85004772827.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/8f3csfbfvp62irfrb6k9clv8f9/48833315780.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/1vp1ab4gis3n7fvolurpn92hco/mumirexaxiva.pdfIn PDF document text
    • http://thebankcardservice.com/uploads/files/mesetud.pdfIn PDF document text
    • http://dongbanja.com/userData/ebizro_board/file/jufinezogikujolijefijep.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/97651866811.pdfIn PDF document text
    • http://tetrafluoro.com/upload/files/tubodaxafufeke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=collocation+book+for+ielts+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_off0000d74d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74D 10876 bytes
SHA-256: f27c09939bbb435834d600b6a4aab81a6bc9e78a5f1f60412ef5ecef8b28a89a
font_01_sfnt_off0000f05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05C 17788 bytes
SHA-256: 20f34075ee7b18fb8f2ff8116c489692cf33e148af92b37220fc3bf0dc84e8d7
font_02_sfnt_off00011e57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1