Malicious PDF — malware analysis report

Static analysis result for SHA-256 9425f02c5f0c5470…

MALICIOUS

PDF

80.4 KB Created: 2021-09-07 16:04:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c05435ad526c3c5d27f22e1874ad6897 SHA-1: cc6362559626fa802043b9bc70d5d89ceb9a8862 SHA-256: 9425f02c5f0c54705f579bd2992d71dc00ed746abdfb2cdb9873fa84fa767f46
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload storage. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a campaign to distribute malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://bouveau-consulting.com/userfiles/file/sumewugasazisekadewadoti.pdf In PDF document text
    • http://119hero.kr/userData/board/file/64841427704.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/bafoxemazenofi.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/78203999363.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/56497631928.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/pevadujefofasaroliv.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab28521330d---8805933765.pdfIn PDF document text
    • http://envigest.cz/upload/file/11645163869.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/a2f42bc37108ef7aa4b1c0cd91a09786/27988742851.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160767bc5351b1---48400469076.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c961a0f3988---rumababuribu.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/5h2meus3pbbkvd4qfqtl6fmpra/fidojinixetarijikexa.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/a7f1a1b04670d352a69d70f68f21a5d7/vasogodirat.pdfIn PDF document text
    • https://www.totspotdaynursery.co.uk/ckfinder/userfiles/files/90369763062.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2a495be042---firizabolaxikulogimore.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16100df59c02c2---jovazekutagolusigo.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/shd1uhu3795an5ik98oqn27vf2/75241192610.pdfIn PDF document text
    • http://tochalco.com/uploads/files/87020822384.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073785328d74---17979716241.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/22156195839.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c47116e1933---63635590552.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/masazidemazeremamigupul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=very+hungry+caterpillar+quilt+pattern.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_off0000d5e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000edfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFC 11008 bytes
SHA-256: 1578a4cf43665387eca8f64a002735aa70a186d7f2408e71f6c5ffd764fc1793
font_02_sfnt_off000106f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F5 17520 bytes
SHA-256: ec7a9611148ac16ebfee268bb701cca526ea2ecf96f208dc7d3bed452d7fec34