Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8428ae9309fbad5…

MALICIOUS

PDF

83.4 KB Created: 2021-08-18 14:18:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 40851a7cea6855c2b679489011f14df0 SHA-1: 70aae32803c9c43104ed270e9f9a8d606a97d74e SHA-256: d8428ae9309fbad5d160278c3aa23d7ab9948d88601b54c5592b559756162f46
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to lure users to malicious content. The document body is unreadable, but the presence of numerous external links and the high ML score strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://jorakaygame.com/ckfinder/userfiles/files/turadovefemir.pdf In PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e8b59a2cac6---rapivitoguzupigagigimide.pdfIn PDF document text
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/cd5fhq7e0hkdss0o4criaggp84/mudofefubabib.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/valerirovewin.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160bfaa8fe2586---47813934535.pdfIn PDF document text
    • http://jngf.cn/files/file/53605365713.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a74445ddc4f---zazogiwuxafagudapugiwe.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092b3de4e1d2---65492381005.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/pibefavuzujubo.pdfIn PDF document text
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/96041580e14d50cff36d9bae9d9a6784/zotegukegifobu.pdfIn PDF document text
    • http://wernitznigg.at/files/zavakeve.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/f8bd2444511c0a7c43dcebdde771fca7/gixepivemuwupokemetaj.pdfIn PDF document text
    • http://veitali.com/upload/files/luvimebubosesolu.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/paxopenogo.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/34140934603.pdfIn PDF document text
    • http://aven.su/userfiles/file/kusowutixi.pdfIn PDF document text
    • http://xpeedon.net/userfiles/file/20210816103120.pdfIn PDF document text
    • http://dilimkebab.com/userfiles/file/fafanituruwobof.pdfIn PDF document text
    • http://galgalesh.com/userfiles/file/jililixewoponovaj.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070c70c0dff1---zesurovijuse.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/melagajasozotef.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16091a2a553854---43206336557.pdfIn PDF document text
    • https://onecre.com/images/content/files/10697658037.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=free+download+partnership+agreement+template+south+africaPDF 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://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_off0000e1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E5 16512 bytes
SHA-256: f87aab387197a99f08f0bb734e6f0cfb34b57f3fbf636cffa95bc6928c040826
font_02_sfnt_off000124d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124D5 11228 bytes
SHA-256: 31b718942bb746a8b7a984f86c120f2572d341a7fcdfad332f3307c1725efc77