Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb5bc4d88a759efd…

MALICIOUS

PDF

75.8 KB Created: 2021-06-23 22:38:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 3c5d575a5e8bbf88db8ac493b123e0bf SHA-1: 94207596090e5c914d6223bcf16bd41ebed55d23 SHA-256: fb5bc4d88a759efd184bf9d9e2f571126095cf8dbdb4748eb40ee3c48c54eaec
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The heuristics indicate the file functions as a link farm, pointing to numerous URLs hosted on compromised WordPress sites and disposable domains, likely for phishing or malware distribution. The presence of embedded URLs and the overall structure suggest an attempt to trick users into navigating to malicious external resources.

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=2003+gmc+envoy+manual+pdf PDF link annotation
    • https://imagebeaute.fr/userfiles/file/62007311347.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7805e930f---bozuwunugotowuzegujusu.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/0v8virhqfmp1pako16fhntn140/14251180797.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/99507837673.pdfIn PDF document text
    • http://davidlbrooks.com/clients/868292/File/6239209861.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file/%5C/20216311862779.pdfIn PDF document text
    • http://nuitsdartistes.eu/images/file/xazesofuziwuxonajupevaro.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/ijiqdqi1k70cfh9rg27dgaasso/30903356861.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b442c8b8ddd---xanepoduwap.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/27424721968.pdfIn PDF document text
    • https://dgaspcsm.ro/ckfinder/userfiles/files/34761158447.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d53afeda90---35341148756.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/4c49d0cd20d8e961f4ed6dac1fb50c40/gegujek.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/2e330133b74054c587047d561404536a/81917808240.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/17339192351.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098c66d73cfd---29754605558.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_off0000e97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE97D 5708 bytes
SHA-256: ab86954a8859e1fef95e7c106dca2651fc30c8cd788ab4c092f7772f267a7d64
font_01_sfnt_off0000fcf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF4 10464 bytes
SHA-256: db57628fb54ad1a2dc6bb2f7fddac73361c2da12a01083eb26e56bb98d7afede