Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a1a153f5860a45…

MALICIOUS

PDF

75.4 KB Created: 2021-09-18 16:19:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 881aad7f179f2780c1e22782919231d1 SHA-1: 125a9cf2e20d106f035e374ddda71ef6ebcc3a40 SHA-256: 13a1a153f5860a45a580885bac76f6eb6d223410fb25579dec63192d7f436b3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://mayersoffice.com/userfiles/file/pukirixiguramulafugepalur.pdf In PDF document text
    • http://alfadent-volg.ru/images_uploads/files/fikatixam.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/zumixenokebogifafozag.pdfIn PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/rowiwenakajozegemazi.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/m3kcvu525eouor46h3kg97kpf0/zezamogimezafizugeloxu.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/64089985304.pdfIn PDF document text
    • https://pomacanthe-art.fr/imagebeforeafter/files/vojufopuxafumipifap.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/a985a8bb7efdcd172cdf80b46b4b95b8/60970904198.pdfIn PDF document text
    • http://shmgec.com/Uploadfiles/files/60583049993.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161433cdaae25e---44556031667.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/319d07388811fdfa5cc25cabc4a2fcc1/fubusedabaroj.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/69558985645.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/33403322495.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/wefewofatetipiremifa.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c91d2d312---38769566743.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/28668678212.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/3877475961.pdfIn PDF document text
    • http://linhkienhunganh.vn/luutru/files/doviwexox.pdfIn PDF document text
    • http://contua.org/userfiles/file/zazomikapatixesiji.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/daxedenamikuwejed.pdfIn PDF document text
    • https://bike-accessories.supersites.gr/content/ckfinder/files/34321865345.pdfIn PDF document text
    • http://photonart.nl/phpcmsys/file/zajanuguromudo.pdfIn PDF document text
    • https://freebcard.com/ckfinder/userfiles/files/25108352717.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/xoroguwaweritajesa.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/xefinebadolimuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=demon+slayer+full+movie+watch+freePDF 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_off0000c034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC034 10968 bytes
SHA-256: bdd0a6f336589e5794094ad9eb9f479b045c29fbbea4405c7a4e0e34df9f9771
font_01_sfnt_off0000d98e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD98E 17968 bytes
SHA-256: e3d81ea672349cfb238834a6f56368ed069f869c09dfeb827af28202e99adb1d
font_02_sfnt_off000107a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1