Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4fb61fff700becf…

MALICIOUS

PDF

106.8 KB Created: 2021-05-19 23:28:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: b8d0a8145fddd778ade1d859fa99c3df SHA-1: 743345d37f74d3ea5bd36da14cf4d4b3ed34760c SHA-256: a4fb61fff700becfb5230255c64ea51e24f06f7b668307759fec4df84a3dacb2
156 Risk Score

Malware Insights

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

The file is a PDF document that contains numerous links to external websites, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body, though heavily obfuscated, suggests a lure related to a 'vocabulary quiz'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/l3488bt78pa9inlur41cdgpe9n/59544927956.pdf In PDF document text
    • http://amatnieks.com/pictures/image/75906311865.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/c612d5454327643e2cce4da570a2f9f0/fiwokurojuxinesa.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c78d0953aeb18383e9612f9f37654d99/vazazolazuwibidarogedon.pdfIn PDF document text
    • http://pelesiuvalymas.lt/i/File/gujiwuvolozoxexineg.pdfIn PDF document text
    • http://www.odnpoznan.pl/fotki/file/file/31928676330.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0897a967b---futovisurojorozi.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a954663a5c---lemizoluperoz.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160724362f130d---70338818138.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/salewasapojaralagixo.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608cc0780295e---mabat.pdfIn PDF document text
    • http://vonkoenigsmund.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb678b4038---35650684894.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160725a0aa12d0---kazomuporuwosami.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/480e17f4f1def0e02e826f1f543a17d6/16283237710.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/~3/1KS0DP0cxss/uplcv?utm_term=realidades+2+3a+vocabulary+quiz+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015da5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DA5 5808 bytes
SHA-256: f7c98f3cf7b3235651026fc3fdd0974f6a36fc5e8c1436c63147f4f6c2d0964e
font_01_sfnt_off00017195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17195 13540 bytes
SHA-256: 830495d8ed4f6a48b936e5eb8b8476c200ca2d170bcb25579378f0073d58022b