Malicious PDF — malware analysis report

Static analysis result for SHA-256 40cf5bfc83c5005d…

MALICIOUS

PDF

84.3 KB Created: 2021-09-11 19:18:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ca9d39bab3dec180c4e288db39529a9a SHA-1: e247272100a92212af9d910c9cada66f72ead10b SHA-256: 40cf5bfc83c5005d02e473020ae46359193a77063039d29e5271d491815a0f41
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised websites or disposable hosting. The presence of multiple PDF link farm indicators suggests an attempt to direct users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://fusheng-vietnam.vn/admin/webroot/upload/image/files/346707296.pdf In PDF document text
    • https://foundationkuzmanov.com/files/binuloralefi.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16139b3a888ea0---1501358617.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/lumip.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/29408681973.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/wonira.pdfIn PDF document text
    • http://etalentlink.com/uploadfile/file///2021090401361027.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/wewewifi.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/fimapodipopunagujideja.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/89160746933.pdfIn PDF document text
    • https://uclerbaklava.com/resources/file/xevoso.pdfIn PDF document text
    • https://badanie-wody.pl/galeria/file/94367135662.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/lomerinibake.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/sosil.pdfIn PDF document text
    • https://alpasol.e-giant.net/upload/files/14799406601.pdfIn PDF document text
    • http://letsfinal.com/userfiles/file/71458966912.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/96249140034.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/20179438173.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/687e38d52757f24ba534a7e47946f6b3/14921358494.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a143daa0c7---jifazovujemigugujazawudaf.pdfIn PDF document text
    • https://berbagiangka.com/contents/files/55021746839.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/13934881284.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/62363031950.pdfIn PDF document text
    • https://mtestbd.com/assets/uploads/files/65711740135.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/61777654786.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=star+movies+live+streamPDF 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_off0000e386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE386 18692 bytes
SHA-256: 0e3d77ca99fa3d28d192c6d6b5da0d1ba3bd834be701d92d28997976f0b8c014
font_01_sfnt_off00011432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11432 10304 bytes
SHA-256: b525ecc102eaa4baf541ccfcafa6b5129676af4b11ff1da84f65e53fb38e7bcd
font_02_sfnt_off00012b72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B72 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1