Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b6c91180c434c3c…

MALICIOUS

PDF

106.3 KB Created: 2021-08-01 06:45:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a5f3a92e0860a09fc8c691e3ed1a154b SHA-1: b3d01616e847659e7348da48cf2c7a1f456badab SHA-256: 4b6c91180c434c3c56b54942885d2d6b8e1f20ad698fd4b08dcf543d45e70842
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of malicious document delivery, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://smidgel.ru/uplcv?utm_term=what+is+similarity+attraction+theory
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c677cbb0a5---sipidi.pdf
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a0c04f1be---86908908335.pdf
    • http://a-kamen.com/userfiles/file/64420556517.pdf
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/e6dd80314bb9bdb5a4ac035ed5e7c61b/mududoxofoxusojonox.pdf
    • https://turismoporsantander.com/aym_image/files/riminebisinubijafojasolut.pdf
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/2bca7eeafe5c56feefe7270c557b3e66/56348703617.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16105c79ebd76e---nepagabelumimovanis.pdf
    • https://jnvhardoi.org/ckfinder/userfiles/files/xivuritoz.pdf
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/407d4b028a72c9de489cc3a0369136d5/16398436109.pdf
    • http://carlaschroyen.com/content_docs/91261998377.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/6fc57093a76834c858432992d2ed4d45/41475816371.pdf
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/pibubapovokikevok.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b06c0a97c4e---50268551963.pdf
    • https://abe-rdc.com/userfiles/file/kosadezob.pdf
    • https://yasacompany.com/upload/files/35431531908.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607add3490b5f---77547194685.pdf
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/8h3the4rivbfbrtgcfhjv5eeoh/mifizegefo.pdf
    • https://perfecthospital.net/FCKeditor/file/59536456669.pdf
    • https://a2designbg.com/userfiles/file/99944427818.pdf
    • http://architettipassarinmarzotto.com/userfiles/files/22453813033.pdf
    • https://fotobolfestmeny.hu/mvc/userfiles/file/21380196483.pdf
    • http://gwardiajuvenia.pl/zdjecia/fck/file/maxoridoduvixomuxekon.pdf
    • http://tribo.kz/userfiles/File/setokozewam.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c85fe0ee16---vefasosemavuv.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16075e89c65617---21389250435.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_off00013ce5.bin
bbbf5a4e5b8b7ffe101c19c1d2d7110fcffec39d221878d9fd257032d0eb21ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CE5 17372 bytes
font_01_sfnt_off00016a85.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16A85 16792 bytes
font_02_sfnt_off0001829c.bin
c05716b51b8919594809dd930071db05e607da45075513ad8f42076839de2737
pdf-font-stream PDF embedded font (sfnt) at offset 0x1829C 10604 bytes