Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a64393576305fb…

MALICIOUS

PDF

73.8 KB Created: 2021-09-19 17:45:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 94fdc86e91bbba04a8345eb24a958f15 SHA-1: 28381815023629135756117ccad0f286fd742592 SHA-256: d8a64393576305fb2f716b0053140cfe2312652eb9e047b971d6e40f8eca2efd
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting. The ML classifier strongly indicated maliciousness. The primary attack pattern observed is the use of a link farm to direct users to potentially malicious content, leveraging compromised CMS upload storage.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://pixomot.ru/uplcv?utm_term=url+to+mp3+converter+online+upload PDF link annotation
    • https://palezieux.com/ckfinder/userfiles/files/41380330625.pdfIn PDF document text
    • http://elskup.pl/images/assets/file/20730624295.pdfIn PDF document text
    • https://cet.sk/res/file/sumegidizajanunubuzu.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613105ed2a1e4---patamibenut.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/96463136595.pdfIn PDF document text
    • https://bestrecycledautoparts.net/images_i/file/kadogajuta.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/vitabivumevipukax.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/warepeduxot.pdfIn PDF document text
    • http://schubert-hh.de/image/file/35849387732.pdfIn PDF document text
    • https://giverny-bkk.com/upload/files/lawatafowofakavuxos.pdfIn PDF document text
    • http://wirtrauenuns.ch/images/file/lilitizibuti.pdfIn PDF document text
    • https://cet.sk/res/file/93577616458.pdfIn PDF document text
    • https://castilloexterior.net/ckfinder/userfiles/files/2518688766.pdfIn PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/23578834023.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/2197082948.pdfIn PDF document text
    • http://uniqsofttech.com/userfiles/file///11160539807.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614137c889e6e---42412137552.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/topukomufaluzumomugapumuz.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/murogekovovulosonole.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136bb0cdca34---gexikogikomatofe.pdfIn PDF document text
    • http://piemonteforyou.it/userfiles/file/84529564695.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202109132342316739.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613759b391304---bukogifobelolugitixol.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/kunupadakor.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_off0000bda2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDA2 10852 bytes
SHA-256: d13d73f3f0d0132ed6ad5cb7ec36da5e4ab0cb2563ee1f556e1049ba887c3f3d
font_01_sfnt_off0000d6ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eebe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBE 16832 bytes
SHA-256: 690d9699db2fa516dccbbea98abc4467c4ed2ff88461557135b0b269e250babb