Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b2ae9ec9f524d4…

MALICIOUS

PDF

89.8 KB Created: 2021-09-19 00:52:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f11d99d66b48d53403b1b31d107aa8bf SHA-1: baa3a0934afc7ac1fe12f99d6d82713ddedfd5b2 SHA-256: 99b2ae9ec9f524d44c606e9061b6d10e5fd66d019eae10b6a3e7b3ce8ebd3fae
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/1b9382a15a2828ccb943be78768adee5/40519533417.pdf
    • http://yljczl.com/uploadfile/20210911022546973.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1613437c50bf37---pifunimuwimovuwokukexidam.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613acb9227874---gijozaliwozavilen.pdf
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/7329723219.pdf
    • https://dom4m.de/userfiles/files/vawizewojumi.pdf
    • http://xiangzhuan.tw/upload/files/fudawariw.pdf
    • https://polresseluma.com/assets/ckfinder/core/connector/php/uploads/files/55568514492.pdf
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16134566281684---kuzebenigapebewulatinewaj.pdf
    • http://mebco.ru/images/file/49483543770.pdf
    • http://tuderprogettazione.it/userfiles/files/dowojoxived.pdf
    • http://jun-travel.com/userfiles/file/9567961263.pdf
    • http://kimwendelldesign.com/ckfinder/userfiles/files/60384627616.pdf
    • http://fd-health.com/upload/ckeditor/files/bofujuzepizu.pdf
    • http://tecsun-moscow.ru/docs/file/77506375234.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408f4b02c87---61902597506.pdf
    • http://geyikkimya.com/userfiles/upload/file/riduz.pdf
    • https://pointwebhost.com/calisma2/files/uploads/98080155133.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613add10d639a---sududigojil.pdf
    • https://www.hkha.com.hk/ckfinder/userfiles/files/jezafesuwojovogopo.pdf
    • http://polkovnik.su/upload/file/34489716781.pdf
    • http://paitoonbox.com/userfiles/files/66227776663.pdf
    • http://tks-forever.com/upload/2021/09/09/file/keguvumitezavubisatevoro.pdf
    • https://kaemsp.org/upload/editor/file/wotizimupujud.pdf
    • https://texigo.tw/upfile/files/2021/09/14/xifixofijojinemezuwutilog.pdf
    • https://pfhotel.gr/ckfinder/userfiles/files/25746697283.pdf
    • http://danchrisjewelry.com/userfiles/file/zifokunabu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=chrome+extensions+black+theme
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8b6.bin
bec87e242951bfa0f3d626ef3d013a4d358d80048ad57adb012562eb83b10ec6
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B6 18340 bytes
font_01_sfnt_off00012855.bin
732d51c965fc8d57ba6ff335ee22856db1bc5f980e8ab0cbb1b25a8e41cf357a
pdf-font-stream PDF embedded font (sfnt) at offset 0x12855 10860 bytes
font_02_sfnt_off0001414e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1414E 16792 bytes