Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b4398e33716bdc5…

MALICIOUS

PDF

71.4 KB Created: 2021-09-29 11:49:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 8d12ca61ae724266e863a4f85db5f6b4 SHA-1: 78981360c45c286ad3a8b136b42f5a0ac20f1398 SHA-256: 9b4398e33716bdc5f207c406e94c1fb544808d173e3a8b9b75dc7200c4831c95
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The document also features a large number of external links, many hosted on compromised CMS uploads or disposable domains, suggesting a phishing or content-luring campaign. The primary attack pattern involves using the PDF as a lure to drive users to external, potentially malicious, web content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • 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.
  • 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://infrive.ru/uplcv?utm_term=behold+a+pale+horse+1991+546+pages+pdf PDF link annotation
    • http://kxnjl.com/userfiles/files/naxilus.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136007168ff0---54906624890.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/73150738335.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/juvizugen.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613549b19d6b9---bopiwa.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/73313925963.pdfIn PDF document text
    • http://spokoino.ru/i/upload/files/53119548808.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3af153e26---46053456780.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/94860570627.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/04be77c228533467f9393c8b3cd6754d/bapaboponu.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/58412504405.pdfIn PDF document text
    • http://hbisan.com/userfiles/file/68880942982.pdfIn PDF document text
    • http://deltools.com/userfiles/file/52129368808.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/tqfm9bqgoqem55grk4darhp3n5/67615265564.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/jajogenukavirosikeruke.pdfIn PDF document text
    • http://0953057778.kad.tw/kads/ckfinder/userfiles/files/50743225739.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/kudesejomuxajav.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134d9394fd1b---wokexaketirubabufifos.pdfIn PDF document text
    • http://clingac.es/d/files/65547461733.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/sunobuzegexonobewop.pdfIn PDF document text
    • https://foodbiz.bdata.link/upload/files/buvipamoraxakow.pdfIn PDF document text
    • http://didopack.com/files/46052722276.pdfIn PDF document text
    • 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_off0000b170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB170 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c987.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC987 11136 bytes
SHA-256: 304e613be66174abdb3c37655065300c5c399f10b5259a1f2b351c4e48c1d146
font_02_sfnt_off0000e388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE388 17900 bytes
SHA-256: ce08cd488096253eb61cc58b39310d11fb42243fa09913c079a716aa65cf85b4