Malicious PDF — malware analysis report

Static analysis result for SHA-256 7547c81b52259cc8…

MALICIOUS

PDF

89.3 KB Created: 2021-07-08 09:58:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 20a6dc763bb420694343d6b287c1dddd SHA-1: b7d66894169498c4fefe7e9c75e74a3ef4a7d59f SHA-256: 7547c81b52259cc8c861608e800a8d0b71b2f600033e8d839dc8ca6cdb4b47ac
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 CMS upload directories on various websites, indicating a link farm strategy. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of multiple distinct hosts and the use of 'utm_term' parameters in some URLs further support the link farm and potential phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/601edf32a38388581cc4da1fe23b14d6/goxufi.pdf In PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b1682a1e2ac---89779891372.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16088f81a78c59---42368961289.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/39c33d8bc73421f204a0276af27ff640/17542685604.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089231275412---mofuradevexosuroxovu.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/b0bc6cfba933182b75e62894b03aa6b1/96091652953.pdfIn PDF document text
    • http://pokeocncafe.com/uploads/files/62989701039.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6f2f7a77e5---vunalizomu.pdfIn PDF document text
    • http://www.aluvascientific.com/UserFiles/file/pazitapepepagaxiki.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609cabc6a4649---32925331582.pdfIn PDF document text
    • https://xanbiente.de/userfiles/file/51095817863.pdfIn PDF document text
    • http://mlkscholarshipsmilwaukee.org/clients/f/f0/f021f13c5c598389be7e913a1ae626ff/File/fabadedogogo.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e32298ed000---didevubolikufijugakiwuki.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b5c53abce---92401736923.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f609a71b90---54099698661.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/90934474499.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/9848d3bcbc6d4377beb2c453c5fe8985/69266018808.pdfIn PDF document text
    • http://tokyoracing.hu/userfiles/file/45907480601.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210624055717.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/6eb7e9e1ec7be4178a65536a65cfda71/romakuw.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160925b72319c9---pimewimimemuvuwukine.pdfIn PDF document text
    • http://mesahighclassof63.com/clients/79820/File/43738438026.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160aca94feef98---tefewuru.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/92h3jde75u31eckf6mrcinuedt/31505318876.pdfIn PDF document text
    • https://autotrans911.com/thread/admin/uploads/file/60452749097.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=if+the+world+should+end+sheet+musicPDF 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_off0000fa9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000112b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112B6 10716 bytes
SHA-256: 338cebdb5ea84596848ed9331f08b8c389a4b9bb7079a5d26e4203df5d6cb558
font_02_sfnt_off00012b29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B29 17148 bytes
SHA-256: 90ae3958cdaddfdb3a878ecc78d21b32c2072360a796a1216c87b7292499ca87