Malicious PDF — malware analysis report

Static analysis result for SHA-256 efef8c57db0a39de…

MALICIOUS

PDF

69.6 KB Created: 2021-10-02 22:30:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5f960979d1445da3ea5436c64fbc564e SHA-1: 3f3e99474d04855fc5ddddf5b277a42176e195e4 SHA-256: efef8c57db0a39de0da5ab1f348388d565c076549343fcae3948058f49063b1a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to a variety of websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports that the document's primary purpose is to act as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://huntic.ru/uplcv?utm_term=making+pastrami+from+corned+beef+in+the+oven PDF link annotation
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/gofaxu.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/95853252532.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/79233286725.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ded1acc08e---dopizojonimila.pdfIn PDF document text
    • https://aokman-drive.com/d/files/lokudoxonisum.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///56627120941.pdfIn PDF document text
    • http://innotec-industrie.be/userfiles/file/rotopaxik.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/ramofidexabojutiti.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/ferabojafilumari.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615322f4c532d---59576773963.pdfIn PDF document text
    • http://pxmonastery.org/CKEdit/upload/files/57908302095.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/76744656665.pdfIn PDF document text
    • http://ceomit.com/fckupload/file/kenuk.pdfIn PDF document text
    • http://soepcentrale-dekeyser.be/userfiles/file/daniw.pdfIn PDF document text
    • http://dotykbylinky.sk/_subory/subory/memudon.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/98685699931.pdfIn PDF document text
    • http://vietcem.vn/public/default/ckeditor/files/46659898628.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/87288133180.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/3430408128.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/ea336a2263b23df7e0d1c45155320728/38539200258.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/fesovavigijifijopitenetu.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210920064459.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4c8acae0d---kifitapivibe.pdfIn PDF document text
    • 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_off0000b165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB165 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c97c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC97C 11312 bytes
SHA-256: a637fcf85b0992fff7d8fae7abe32f528c33f627bd89be377557242e99802826
font_02_sfnt_off0000e384.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE384 14680 bytes
SHA-256: 312b1f177dd3919cdc17a392afe90137691e1ba215c78f1e51ac2841b02e8c99