Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9919ab466894a84…

MALICIOUS

PDF

90.1 KB Created: 2021-09-07 02:26:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 1500fdbe15010bb01ce0799eb3eb5f2d SHA-1: 4d16c785ef8c4cf6bb2ffe58b3e8a6ce1b1eeb73 SHA-256: f9919ab466894a84ee217c40fa6a4bd043430f9062c3cf5257fe114ee7c645b2
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories on various domains. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm on disposable hosting. The document body is unreadable, but the structure and URL analysis suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/956ec7017111dbe0d9df1ba9bcff7db0/vaxudejadazixupox.pdf In PDF document text
    • http://growourworld.com/clients/83159/File/riguzawupasolagiwav.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160722e937bc4b---vizip.pdfIn PDF document text
    • https://wcfkenzi.com/ckfinder/userfiles/files/53089527572.pdfIn PDF document text
    • http://td-mg.ru/uploads/files/44011180289.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/nodil.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/435e02cedcbb955ebb4e61e4fce399da/23839033259.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/2s3ecub3rvcjqln33cvv3hdkbf/wogaxiwomina.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/g4dv3ut829m5vqm4u86q44ls2q/fidutusagiso.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ba39f1d41---mosafevirevaraw.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bbfe2c1ac32---5009493618.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/36d2625fd179b59f1d7ae170910150e6/70028482375.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/98887832986.pdfIn PDF document text
    • http://ranahytta.com/ckfinder/userfiles/files/lolarokitajatudis.pdfIn PDF document text
    • https://osakadentalcare.com/contents/files/gulifogidujewija.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021051123292386408.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbdc7839827---mofada.pdfIn PDF document text
    • http://hangnhatbanonline.com/upload/files/namixi.pdfIn PDF document text
    • http://web68s.com/upload/files/jaxumopakegofusegaludal.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/witujaguvalawinewurerejen.pdfIn PDF document text
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/5e8fe3f2ebe88cae2310547a0bfb93f4/42170096278.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f34b25b3e74---96455273965.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/6ac58714448009d77d7aee8018e17cc5/godideburadadopukevixinam.pdfIn PDF document text
    • https://gaziemirkentkonseyi.com/upload/files/22122593738.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=esame+dottore+commercialista+2018+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_off0000f922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF922 11164 bytes
SHA-256: 82feff72e77044fff0bc05a77d6e950f50c28b229d01a4453d8388370ae1d7de
font_01_sfnt_off00011348.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11348 17972 bytes
SHA-256: 814b07c4a074e9339439ef075b8b58907a9cebc6f49e9297c4992a936853c662
font_02_sfnt_off0001429b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1429B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1