Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b5df0669cb70db…

MALICIOUS

PDF

74.8 KB Created: 2021-09-06 21:49:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 30977e4fd0436094c0a1b39339f73f8b SHA-1: d2dbf025786d11fe4db76950a89108eb474f6a62 SHA-256: f8b5df0669cb70db0ef59ce60f187e588639c8f4c2254d0ba867f87c92ac89e0
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to PDF files hosted on domains identified as link farms or potentially compromised CMS uploads. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure and URL patterns suggest this document is designed to lure users to other malicious or SEO-abused content.

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 http://loaamtran.com/files/usersfiles/files/51257311667.pdf In PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075d0be389d0---leraw.pdfIn PDF document text
    • https://jairdefreitas.com/ckfinder/userfiles/files/nugazuk.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160940187aab30---joferuzofesewimanosid.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/jufusobuleve.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/5f3fcda7e29281fd9670e6a3ad258070/tawesoripatuvin.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610e338356d2e---71800899860.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/85010291983.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/povegi.pdfIn PDF document text
    • http://veivel.com/userfiles/file/2109937523.pdfIn PDF document text
    • https://www.elitelawnsolutions.co.uk/wp-content/plugins/super-forms/uploads/php/files/94enfrtlkhnaldjtqio7qolf67/73421877797.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16073d88fd4216---23591864597.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5060295be---pexokixepawog.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/092enjppcgn7p4f8dfgect5nco/46801856630.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/14716909105.pdfIn PDF document text
    • http://harasim.cz/uploaded/files/66409321570.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/88085417716.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/puziburozerofaxe.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160b4948b89ad0---80309955327.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/37dc58010a7357965daa4e7394bd49f3/11800829410.pdfIn PDF document text
    • http://vnos.vn/app/webroot/uploads/files/lekaxejazujar.pdfIn PDF document text
    • https://nomortiga.com/contents/files/mupuxudejamevamiwawugu.pdfIn PDF document text
    • https://hagepoorter.be/files/files/povanegebunilufobevesegaf.pdfIn PDF document text
    • https://mimpishio2bet.net/contents/files/83827629201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=american+diabetes+diet+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_off0000c12a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC12A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d941.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD941 10736 bytes
SHA-256: 41ce52689d5e737a899eb2d238e7479026928ed5ebeb439e1c69840b2a054af3
font_02_sfnt_off0000f1ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1AE 17324 bytes
SHA-256: 7bfc559ee1b4ba0816e7253507d379301bdecd77aa4d822cd0a642efefff535a