Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c90e937729b9deb…

MALICIOUS

PDF

71.4 KB Created: 2021-04-08 18:10:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 644a634457edaffe29f1805719e96e41 SHA-1: ce368b4444f7ba5332a0b8a8b65eb5acc1e26b01 SHA-256: 8c90e937729b9deb5db58cb937105b096d7f9bfc502ab86a82e69a7324925048
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable or suspicious domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt, likely leveraging embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://aboss.by/sites/default/files/webform/31226501773.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/fabifuturofutip.pdfIn PDF document text
    • https://www.cdcplumbing.com/sites/default/files/webform/contact-us/sawifujemenolezaf.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/61975266633.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/96479551545.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/28941778760.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/89971565628.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/30253637425.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/julojulixizegusu.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sakobonomoduriv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=digestive+system+of+grasshopper+pdfPDF link annotation
    • https://lib.asu.edu/system/files/webform/vabomabexajamoja.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/fapivo.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/17420147243.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA59 5584 bytes
SHA-256: ab22f3d4806196ffd29c2841e73812130f30878cad915f83c61f001d687bdb9b
font_01_sfnt_off0000ed41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED41 10280 bytes
SHA-256: efeffb66311c552d2c4f953c6c458e5daf0372e01f518870e15bbb31dcac5dc8