Malicious PDF — malware analysis report

Static analysis result for SHA-256 e9e8b5166a86c850…

MALICIOUS

PDF

89.9 KB Created: 2021-09-04 09:29:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 50d47a720f5333b3d65abf67b5346f81 SHA-1: 3457fdfe60aafd5556971ecc9696cc19300952ba SHA-256: e9e8b5166a86c850492fadecacbf9e23fe7e572b9879f1a64dc8d92187686c21
196 Risk Score

Malware Insights

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

The sample is a PDF document that employs a social engineering lure to trick the user into installing a browser extension or update. This is a common tactic for credential theft or malware delivery. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it is designed to lead the user to malicious content or downloads, potentially exploiting vulnerabilities or delivering further payloads. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://onishi-kyosendo.jp/archive/21848379318.pdf
    • https://erdenet.mn/userfiles/file/refilajibepis.pdf
    • http://samurairamenbar.com/uploads/files/sedaw.pdf
    • http://eurogeographyjournal.eu/admin/fckfiles/file/75434678815.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/e137e1553efe780b67fdb130b6914b35/38120001902.pdf
    • http://liyangah.com/Upload/file/75556618159.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104ca7a7ffd6---31954918993.pdf
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/up9vaqmafcnss174bf7mr9hcc3/famamubosebosaloxaf.pdf
    • http://visit-pune.com/userfiles/file/25125747497.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/c7a7e4c4951687b3883ef2c91b1110d2/gefudinelagijasoxa.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160cb0e7ae80ec---tovefeta.pdf
    • http://faceconnects.com/ci/userfiles/files/xojuzu.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/6df8a284ae42f3c39e0a1980ffc31802/93790148356.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16098b7a209ed6---7669246075.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160989f8e6c01f---46501816603.pdf
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/7dd1b76cd046e5f4e8d319a5e521db99/zalafujozikotenibog.pdf
    • http://proximeo.com/ckfinder/userfiles/files/wasiwudamesukebesadufu.pdf
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/5e8313c0372702519cc966740bd59c0b/rugusa.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/upmkbhqd6h2f5obb52qdje16a1/73423127584.pdf
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/89239078994.pdf
    • http://minhquoc.vn/ckfinder/userfiles/files/52012388221.pdf
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16070a7ccb6b78---zewupi.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160853828efd59---77239813398.pdf
    • http://baocaosuhoatoc.com/luutru/files/98500526545.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=dla+form+1822.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e154.bin
19b9020322d4e77be77989a818d9763877a3855ccbf76158962b406280a2053d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE154 10512 bytes
font_01_sfnt_off0000f953.bin
25b783ceb6ffc0584717f11a81ebb427f36a32e1cd4c02667c39ed5eddf083e0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF953 17928 bytes
font_02_sfnt_off000127fc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127FC 16792 bytes
font_03_sfnt_off0001400d.bin
7ed08afdcb523621fc64ac185b82ee43fbbd47e5d766497fc8648e9d63dbab5f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1400D 17296 bytes