Malicious PDF — malware analysis report

Static analysis result for SHA-256 b98049c777f093b1…

MALICIOUS

PDF

77.1 KB Created: 2021-06-09 21:11:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: fcf986ede1db167e067d9484c705e2b3 SHA-1: a14cd05bb2757c2067fcaf00d91988baca289089 SHA-256: b98049c777f093b178206d9368a86f01e34e91a5816e76ae3fe81d108937c61f
176 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm designed for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing given the 'worksheets' lure in the document body. No scripts were extracted, but the structure and URL patterns are consistent with a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://pistant.ru/uplcv?utm_term=addition+and+subtraction+worksheets+3+digit PDF link annotation
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160733911a6250---gikesanatonuwukaferawofi.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbcdda0b23---sotorigobivirip.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/zusakutikisilalukurifab.pdfIn PDF document text
    • https://stdtekstil.com/upload/ckfinder/files/35266216221.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/714370b263dd8918653ebfb024ff0ca1/2894584714.pdfIn PDF document text
    • http://inwallendorf.de/userfiles/file/nalavet.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a90a2d903d1---6694840258.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160764b2c47fb0---mogunax.pdfIn PDF document text
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/5d8f12056982694bee53fec463ef148b/38622568002.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096abbab63db---solefagefemogebalikolo.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/omem4j5qudpsu56iga3vdj48ne/6145552977.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/9022674723.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/q0022ejcnj88u5fumbmj70r2ef/sobusaxavibosokejitekuful.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b129626b8---49014225062.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_off0000f09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09A 5616 bytes
SHA-256: e21883f97eb142d8df65e3397198829ca7ee873f48f69f9b9f8f798eae94aedb
font_01_sfnt_off000103c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C2 10500 bytes
SHA-256: 219b4042e7c1b7712cfe13c624d331e6f986451955c9f45897e1f0e3498d7e73