Malicious PDF — malware analysis report

Static analysis result for SHA-256 773355eed97d6fa8…

MALICIOUS

PDF

97.7 KB Created: 2021-09-07 06:36:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 79c0728e9911027c9acf9c9e719fc684 SHA-1: 7c265c090f2ffce25ca84c2c8d6618d5d8a76088 SHA-256: 773355eed97d6fa831d23763385313a67f4f362f3322bab6400ad782f24fff97
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lead users to phishing or malware-hosting sites. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://patriabrno.cz/userfiles/files/40503901400.pdf In PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16102cc256196f---balov.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd66ceb1d7b---6789260719.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/gibodolib.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/4c34cc62f61b1dc8da0b5c0a58346fc9/gojesazijokedobe.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/10354221738.pdfIn PDF document text
    • http://flemisterbauldingfamily.com/clients/8/82/82a21d9598fc66f9117a8fb7222c8fd0/File/wotelelebokezi.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16108ca497c609---gosokiwotexakarakalulali.pdfIn PDF document text
    • http://hiro-seiko.com/upload/files/38534949166.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/92192097298.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/16118b3993787b---fagusevopagegagigu.pdfIn PDF document text
    • http://xn--b1ahhafccpgkb2bxo.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4cfb5f42a6338fd109b8c6e88d7d046b/wirux.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/38942134725.pdfIn PDF document text
    • https://5uempat.com/contents//files/sogusej.pdfIn PDF document text
    • http://djk-winkel.de/images/uploads/file/vakesiwilarifivazajefanug.pdfIn PDF document text
    • http://surtek.biz/image/files/20150126_094523.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b5523828225---sasukuvaluloxumifida.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/fadokititiralifelaj.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/q89bogej62bi6917rj3j7d5898/winexilokuworofesudomuf.pdfIn PDF document text
    • https://intervalhousehamilton.org/ckfinder/userfiles/files/lexetifuwamisaluj.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/jaxixujofofuxijolotojojas.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/748484bea1fc8e8a0442d213c6301c0e/73646693997.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210626200130_dgl5wr.pdfIn PDF document text
    • http://alfavs.eu/userfiles/file/47461181164.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/98317342253.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=palavras+cruzadas+coquetel+em+pdf+para+imprimirPDF 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_off0001126f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1126F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012a81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A81 21008 bytes
SHA-256: 9abe8d739e00f01467a627a99c76829a9a88290f58e2840dfeee70f082907063
font_02_sfnt_off00015ecb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15ECB 11052 bytes
SHA-256: 5b1d3383dca06c0f30bd3b13bbdf74fd222d152dbb8734b68dc786a4dbabe804