Malicious PDF — malware analysis report

Static analysis result for SHA-256 33a94ad1170c75b9…

MALICIOUS

PDF

87.7 KB Created: 2021-07-16 15:37:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 3f2ac829438dc25e6240b381374e64e4 SHA-1: 1c0ae92850ae6a592e67e0585f6362501a5188ce SHA-256: 33a94ad1170c75b9c437e7e0e2d1df4a31599d863e0495188c40bc7231f48a73
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of links, many of which point to compromised WordPress sites and utilize UTM parameters, indicating a link farm designed for SEO manipulation or to distribute malicious content. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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://karinbentum.nl/uploads/file/rakaxonotejikoli.pdf In PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb9e694e8a---wukaka.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d3006735520---mabofavugas.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/7209910204.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/35090899774.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/sibefuduxalojokinurarup.pdfIn PDF document text
    • https://miaousland.fr/ckfinder/userfiles/files/19385786993.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/0e0575df499ec81267a4f603bbbd7eb1/gexosu.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160e59410b8916---nidujalonodunudifopob.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/51c1597cab8ff86342359a59c6fca70f/nebenipifovodexiga.pdfIn PDF document text
    • https://ckmandarin.com/uploads/77002374731.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160989aafed722---51084588176.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160799a4679d18---bodiz.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/9hkt4gh6ihleqh2eioeisverv4/77622822762.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/eh2od0dog7r3jk28h51n6r76lo/xejaxisepavi.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16098c29d2c1bf---40625998636.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e1bbacb732c---74553215544.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16072846663ff8---83049244937.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/0cd8411bc1b6157418b438c80c02ec41/27865628702.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085591b51515---71838980750.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbd554a9f0---lidutudumadap.pdfIn PDF document text
    • http://esipro.lu/userfiles/file/64144529456.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608783e1d6f1f---zimakaguloluxup.pdfIn PDF document text
    • http://clinicaveterinariabilancino.it/userfiles/files/65635879961.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=easy+lunch+meals+for+onePDF 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_off0000f32c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32C 10608 bytes
SHA-256: 9e363170f754fb4b11b5f730bb3f6cbcdeeb26493291c2e04a7f84d295bee1d5
font_01_sfnt_off00010b3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B3C 17776 bytes
SHA-256: df60e4b05490a3e0e3bbe2f39dc7155acf796a2761ed00e79ad5c78f3199851c
font_02_sfnt_off000139e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1