Malicious PDF — malware analysis report

Static analysis result for SHA-256 850daf823ea78ac2…

MALICIOUS

PDF

84.0 KB Created: 2021-09-19 03:14:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bca7863fc6737ba2c250911ddb43c96e SHA-1: 8626c77ea972ac31687855e8f558c8b82d45117e SHA-256: 850daf823ea78ac25bf697cf7451e1bfcd4f58b83d2db3f8a025bd8f2d09ba41
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to numerous external URLs, many hosted on compromised CMS uploads or disposable domains. While no scripts were extracted, the structure and URL patterns suggest it's designed to redirect users to potentially harmful sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://thietbimaugiao.vn/Images_upload/files/gopubarukijijakowafeba.pdf In PDF document text
    • http://rinsacars.com/files/others/29607074824.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/44be96b3d5c528596b858b9569d18bf0/lipuxeb.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/zupazanab.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/81585742502.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/40369894902.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6dd2655d6---laduve.pdfIn PDF document text
    • https://vienhung.com/webroot/img/files/2178784268.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/7008302136.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad471c0eed---56287157346.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140372f49d5f---83341923326.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3281a5b9d---25555423141.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/35004521696.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/4652412605.pdfIn PDF document text
    • http://dogable.de/userfiles/file/vefaturefunurevafum.pdfIn PDF document text
    • https://alaqart.atelierleuthold.ch/userfiles/files/46335273477.pdfIn PDF document text
    • http://spiregene.com/image/files/20210907_141403.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/pipopogubixirajalibakoga.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfe31588be---medewotozubifu.pdfIn PDF document text
    • http://radyoislam.com/resimler/files/zurimak.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/30836796864.pdfIn PDF document text
    • https://afmiletisim.afmiletisimajansi.info/resimler/files/fibadikimozarewifur.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/161448465b9b03---62406776939.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=skype+on+android+autoPDF 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_off0000e004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE004 19328 bytes
SHA-256: 82b101c585086d5200173be91553e89ce026f323b89d8144dcafd997f5e14e13
font_01_sfnt_off00011252.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11252 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012a69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A69 10552 bytes
SHA-256: 35c5c4fcd459b022dc738b005e47efa5835cd6d52c7e4f5a37a7af38a4c8b676