Malicious PDF — malware analysis report

Static analysis result for SHA-256 c50cd90988a92f4f…

MALICIOUS

PDF

80.3 KB Created: 2021-08-19 01:31:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 758264764219cbdaa2e780a62b22f474 SHA-1: 331a3c88053ffb0c69b854244983dc18508e52ce SHA-256: c50cd90988a92f4f087e1821339ffefd29e15a87a3b3633f1fdf383b2c09792e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary attack pattern involves directing users to potentially malicious or phishing content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609c026bcb920---witasesuso.pdf In PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16093a5ba98ff2---99362214464.pdfIn PDF document text
    • http://beverleyannes.net/home/beverley/public_html/ckfinder/userfiles/files/wonarirofelabekogo.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/hffb9ag7l33omfnf3mhvqtmhvn/jakoxemapomudozexe.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/dobifuzerumazewudefi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbc346eb04d---37065532601.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/s3qu3e7ltp9eka05gstqoudqrk/gavuzopamekeboligotiwoxiv.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/21833643745.pdfIn PDF document text
    • https://savitravel.ro/ckfinder/userfiles/files/98121967873.pdfIn PDF document text
    • http://neoclassicalmansions.com/uplds/file/70001301797.pdfIn PDF document text
    • http://soupworld.de/upload/file/wedutamobokavifuju.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160713ed49fa57---17078816826.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a7d662a75c---31904719880.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/lawunukov.pdfIn PDF document text
    • http://abnicum.ru/files/file/42465669455.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077cc945fd72---vafinuzegukip.pdfIn PDF document text
    • http://technocom.pl/editor/file/losafub.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/a6e4p3ud2740236rujdre824c0/67288909928.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/32717252618.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/18233086892.pdfIn PDF document text
    • https://primer-spb.ru/files/files/60159960531.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=what+is+romeo+and+juliet+act+1+scene+2+aboutPDF 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_off0000d700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD700 16324 bytes
SHA-256: 813f55156c978d564f087eeb842a508a9eb14bab6104868fa883ed00e4c0be3c
font_01_sfnt_off00010136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10136 11168 bytes
SHA-256: c41761761ca0af8ff34bb04dfb71f8dd2c453bd788e10e0bd662fba9a26eb9da
font_02_sfnt_off00011b3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1