Malicious PDF — malware analysis report

Static analysis result for SHA-256 41d79f9ea8d710cc…

MALICIOUS

PDF

80.3 KB Created: 2021-05-18 17:41:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 0d6c38c39db23fd50a873db55e9e976c SHA-1: 025fc61e66cc926e2fb4c54cbe73765e7d89b321 SHA-256: 41d79f9ea8d710cc8c75d574a24990f4845d88d92f0a8f6960386fd53188f273
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. The document body, though heavily obfuscated, contains strings related to search terms, suggesting a phishing or SEO-based 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://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160826fc348eda---vijadedivetubu.pdf In PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/s6gniq16a6d7951anvcak6anj2/29336226058.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/h1mulmgiti5ljls8evr3mm9e13/zozarasadifafe.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/51087491653.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/dno81472l89h42lv3o6cvm5j91/64729032506.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/743543625609beaec631ca.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/75888499791.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/c62b2ccfd1fd357adc4f5d71c1d7dea7/61823640815.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607a65b5c0d0b---46026640764.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/mixuvavizuvomilusopafozef.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/75148527025.pdfIn PDF document text
    • https://whiteelephant.co.in/wp-content/plugins/super-forms/uploads/php/files/7ff47e6581cf16b6211fa9d024a099b7/biwepuzinenudif.pdfIn PDF document text
    • http://anvlaw.com/userfiles/file/67374756971.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef300a0f88---23237303298.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/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=k%25C3%25BCrt%25C3%25A7e+mevl%25C3%25BCt+mp3+indir+mobilPDF 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC40 5352 bytes
SHA-256: 0b0afd1cb9497d5eb0e3b259624436451f38f91936ccbfcdd58d3ef7caffb096
font_01_sfnt_off0000ee32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE32 12812 bytes
SHA-256: d7eb54992e5bafe55ebb6aa2b132ce3376aabb30acd9c25abc5c939f11e1b9af
font_02_sfnt_off000114a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114A7 18464 bytes
SHA-256: c2db34f2ea6ccc5e7517d524e81c56e570daeebebb0935531551cba4d0cfec86