Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf8878eda31b5f9…

MALICIOUS

PDF

80.6 KB Created: 2021-08-25 09:24:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 8031596060997371349e41b4f0e6c381 SHA-1: 1fff1bcb9109e07e2bde396a662c65f9800c4aa5 SHA-256: caf8878eda31b5f9f3937cacbe9e29374c5db63668bef349d12365ce45533729
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to unknown or potentially compromised domains. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it functions as a link farm, likely to distribute further malicious content or for SEO manipulation. The presence of multiple unknown PDF files linked from the document suggests a multi-stage attack or content distribution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ruiguoex.com/upfile/files/2021/07/13/dibagenek.pdf In PDF document text
    • https://leganordavigliana.it/uploads/file/xotumazageratib.pdfIn PDF document text
    • https://gannat-ltd.com/userfiles/file/guliganabimujijokasuf.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/42761484900.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/faxalirabezur.pdfIn PDF document text
    • https://jss-moms.si/upload/File/sejeropapobefi.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd48a13ea9---78968240138.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/punefimuxetozefel.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/37053212598.pdfIn PDF document text
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/vqjhh210n7nproe7sj0as3stsg/zivejonugugugumirevubilit.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/4ff87c3cb942b2962d787704938d7238/4679742953.pdfIn PDF document text
    • https://mamadona.ru/ckfinder/userfiles/files/18147913116.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/gazafamaraga.pdfIn PDF document text
    • https://tagoproperties.com/ckfinder/userfiles/files/64595417865.pdfIn PDF document text
    • http://ambvetesopo.eu/userfiles/files/70530823565.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/guvitozesofalunid.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/mozuzu.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/10334728958.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609654777616f---78735100113.pdfIn PDF document text
    • http://randalljroutson.com/clients/44711/File/27099574916.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fba25f4cb96---kifuvirepovelapasa.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160f2edd4a8342---janetutetejuzadozodal.pdfIn PDF document text
    • http://www.sanjuktabanerjee.com/fckimages/file/zodomuvogefuwux.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff27baae13---18953660012.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/97b7c6cc44692c29b1c861873c8da3ed/58417609295.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=maxwell%27s+equations+in+gaussian+unitsPDF 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d73d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4F 16980 bytes
SHA-256: ea7cb71e4353a55110d72b51f23b6d95b1e7fd0d6dd318af1e3a5853f0dedb82
font_02_sfnt_off00011c19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C19 10644 bytes
SHA-256: 94df683c39d44877476f8808f8ca7bd3b1c218a49b8c7178e034597a003270fe

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