Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bcf49fd78ef532f…

MALICIOUS

PDF

97.2 KB Created: 2021-06-28 01:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b5baf5543fde7a3aad7ac270abf50cbf SHA-1: ce2905c98f4ea36d8595b987146cdd9d1a932352 SHA-256: 0bcf49fd78ef532f065debdb24afd5146489a8ab3f90de2fbd5a593ba73d1d52
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised WordPress sites. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce17c7d9ba---somokinoteg.pdf In PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/0eec208d8ed9fc32bd57136d223d604f/kijeribis.pdfIn PDF document text
    • http://blesk-stroy.ru/userfiles/files/mewefevatawet.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070c138a1671---zukeleje.pdfIn PDF document text
    • http://4grd.com/cmsimages/file/56380070424.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2dd6af026---8264920887.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/acb7b4915a038feef0cc3103b617b6fe/gozepofumabesawuniraka.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/najitutadizaludokul.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/79394228969.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/94366569618.pdfIn PDF document text
    • http://bigsvatcharasith.com/userfiles/file/7245723703.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/4694d8c50a32cd23b6bebe6c76fcd983/fefebinejefewu.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/51aa787f43b3cc48a1431885c6613ff3/xosoz.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160ab84ae91282---72434389282.pdfIn PDF document text
    • http://ehs1958.org/clients/73155/File/94794187099.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160746e2da876e---50419895774.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/167cd9979bb237549058639455a35bfc/48942122012.pdfIn PDF document text
    • http://theettiaresottawa.com/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/zudebuwex.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/933dcec11f21ab2a3737abfec46ddd7b/nimoxupeberijil.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/8oh706pa4oom0tb4pdogvnu307/gelapugurololexaran.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/d5096620f2c7adcffc551d2d32503c07/xosemanurunirigemarilosel.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160bdd7e687ad3---pubolatuvuwixera.pdfIn PDF document text
    • http://onlineticketreview.com/images/file/76040471329.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16081c4f2dab41---lupowiguzebodajifabuguki.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/28510849896.pdfIn PDF document text
    • http://allasclub.com/campannas/file/zugidaku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=phd+after+maPDF 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_off00011cc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000134d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134D4 17056 bytes
SHA-256: cc70e61d307c687438d723d36406979f33a058e8fd1794f8494763e860f21ddd
font_02_sfnt_off00016146.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16146 10088 bytes
SHA-256: 9726ec8f3a6abded896fbb418088761ee44d0ce99c1bfb3792ec9b97e3173727