Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a942c5979658c7…

MALICIOUS

PDF

76.5 KB Created: 2021-06-09 13:28:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 4291d96e1b3d281cf0ed43472f8a8678 SHA-1: 1747e8bbadb0741cbfb52a19584227c75f83eb56 SHA-256: 99a942c5979658c79490fb3754fd24ac704c0d16704a9a39b823f6f859bbc34a
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for distributing further payloads or conducting phishing attacks. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, aligning with the file's metadata and its role as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/uplcv?utm_term=percy+jackson+camp+half+blood+confidential+pdf PDF link annotation
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738f2592b9d---79727608793.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/33283716883.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606da63e800ce---xizukatesewamu.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16098bdd48a270---wufelejaturet.pdfIn PDF document text
    • http://garderoba.sk/images/_file/84656256233.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b9a4d8b4c---kevuravusa.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/7c43e49d7446d55666949b289795b92e/pamixabometer.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608600d2c4f12---43653290276.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/oqhjca7arji376ita80bclfmj8/53786064970.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160acbe413d1e0---lamuwovirujumazofumunofow.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607d68b662274---13625556866.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc8224189f---6985402813.pdfIn PDF document text
    • https://atamergranit.com/userfiles/file/58316184358.pdfIn PDF document text
    • http://ideas4mypool.com/userfiles/file/4565639191.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/f8ce325945df16077103d536fa0efd4c/kulimedaxagizi.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b2802bbbe---navobonituvezowibu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eaa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA6 5780 bytes
SHA-256: 8e2e9b0616b2b1ab9fa106bb364fd6fd2d43a34ab0c19425e0df6e3603d572b6
font_01_sfnt_off0000fe38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE38 11376 bytes
SHA-256: b478dc37c4dc83be764d488aa6ddd3bba66663cee2f1c864176d3e8b1ebbade6