Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd5c3bb6cfe4806f…

MALICIOUS

PDF

93.0 KB Created: 2021-07-04 20:15:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 33991bef0f48f1dd708ec5d8671fe350 SHA-1: db9fc95e5b9086f2f5a8bc737cd6eeedc7971997 SHA-256: cd5c3bb6cfe4806fa04fde517f1ee151adc2063f41849ec8a7d95973f7a5f6fc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains a link farm pointing to multiple compromised WordPress sites, specifically targeting formcraft plugin uploads. The presence of external URIs and link farms suggests an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9806

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://krisoc.ru/uplcv?utm_term=perforated+eardrum+infection
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb58964deb9---xaropefibivep.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aec8fe33e0b---15723093355.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a7aa7d92ec4---ximinexexamera.pdf
    • https://alnahamgroup.com/userfiles/file/96239752405.pdf
    • http://biosurfest.com/userfiles/files/donisevagevubavetabavori.pdf
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/306mfdhd588pepohf8hnlrth2l/funezelen.pdf
    • http://mitcostruttori.it/userfiles/files/zexiloso.pdf
    • http://flexa.cz/docs/file/jidorivipupixu.pdf
    • http://dgjst.com/upfile/file/mizamakonanepexen.pdf
    • http://makesomenoise.hu/upload/file/38190507782.pdf
    • https://learningsolution.ca/userfiles/files/kizufobudoxu.pdf
    • http://www.euro-fly.eu/userfiles/files/17620594282.pdf
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/218483c989d9d26ad3c728bf25b8ec4c/rodobisurovutore.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609610e4e6ed5---belegu.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098cc7296044---3874296356.pdf
    • http://absolutelyneon.com/userfiles/file/19182027246.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c73e075874---87706861083.pdf
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b4010c86c05---vizise.pdf
    • http://bagumul.com/file_upload/spaw_upload/file/20210629024210.pdf
    • https://holocaustresearch.pl/nowy/photo/file/74223552881.pdf
    • http://shosholoza.de/file/4758680676.pdf
    • http://seksdagen.nl/userfiles/file/969701679.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ded9a33581---tubijo.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608291cc49560---53081451770.pdf
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079345abbccd---84242287903.pdf
    • http://bortran.com/upload/image/file/20210623034318.pdf
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/92383141391707b02746ddf45efa7aba/96311973909.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_off00010a71.bin
bcbae2793236dd3088c36864e446343cab4f3a29bab3fd187451a44dd49a9c4a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A71 10524 bytes
font_01_sfnt_off00012261.bin
c61de1513b33111699dd27622e0303e80e7beaef7a225882ea3844bc225cecf8
pdf-font-stream PDF embedded font (sfnt) at offset 0x12261 16964 bytes
font_02_sfnt_off00014e55.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E55 16792 bytes