Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8800957934ca79b…

MALICIOUS

PDF

96.2 KB Created: 2021-07-26 09:55:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0d5b2739141c0c68bbf949de3fad9771 SHA-1: c066dadb99bd6b91b7005bb071469c9a8ff85149 SHA-256: c8800957934ca79bcf138ae2de98f4e43d7e7edccdbbc7bba71d72bd7c63bca2
212 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, flagged by heuristics as malicious and a fake CAPTCHA lure. The document body is heavily obfuscated, but the presence of JavaScript and the fake CAPTCHA heuristic strongly suggest an attempt to trick the user into executing a payload. Several URLs are present, some pointing to compromised CMS upload directories, indicating a distribution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 9

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://mimpishio2bet.net/contents//files/13181411451.pdf
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/7b88d7a57e805692d33b49e1440eb1f4/22414417782.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce302cc330---biregiwuvibogusujox.pdf
    • http://ehomerealestate.org/images/file/43229763319.pdf
    • http://personnelstrategies.net/userfiles/file/zogazeradogodalodojaliga.pdf
    • http://volkshilfe-vlbg.at/images/content/files/natavabojate.pdf
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/358105971474f729399f3421ae80e086/66984217028.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6b82e06691---83188279686.pdf
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/37346145502.pdf
    • http://uss100.com/clients/5/56/562308f4da1da23328cfd9e5c9f3e68f/File/10794017993.pdf
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/1c8aa3779927c908210f41434987056c/sudodilu.pdf
    • https://belhasasecurity.com/userfiles/file/pekasuwusewilefodi.pdf
    • http://dlevitin.ru/fck_editor_files/files/9770473380.pdf
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/16208383221.pdf
    • http://dribblebar.pl/userfiles/file/litudapanogapunin.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/3e422a9d5eebb0cf1b6cd9151d350dc7/sixenodepilepabe.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a79eb50db28---96846924997.pdf
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a2628055a22---wamapawu.pdf
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/55223205322.pdf
    • https://sinhadventure.com/uploads/file/58508662546.pdf
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/acad3d3r9naojpamkecrl2dpg7/89547273316.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607193477b553---48396241031.pdf
    • http://ildungrice.com/fileupload/fckeditor/file/xejuwelipotos.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=albion+online+light+crossbow+pve+build
    • 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_off0000f2b6.bin
b513d26709e096d752af13fb702f18f131f42685fe268f08341f53f86c3d9498
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B6 17364 bytes
font_01_sfnt_off00011fab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FAB 16792 bytes
font_02_sfnt_off000137c2.bin
c03a30ff2a86c408f6f2f36186da5c1ad25eda47f1b20fa0f2805a05d7f23b2f
pdf-font-stream PDF embedded font (sfnt) at offset 0x137C2 11004 bytes
font_03_sfnt_off000150e0.bin
38db3f80119a50f9945ba5edd9fb88f2824a2b72dc1eef4cbd370b7c73e66f3b
pdf-font-stream PDF embedded font (sfnt) at offset 0x150E0 9576 bytes