Malicious PDF — malware analysis report

Static analysis result for SHA-256 c839eca0ae927f7f…

MALICIOUS

PDF

84.7 KB Created: 2021-09-08 00:10:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7eed38b946b7cce1ca9cd52fcd34ba5b SHA-1: a185d94060f8880318d64c44faa56e788bd92f54 SHA-256: c839eca0ae927f7f102658135805b78ceb4b94eace9fa675382226a401e1c6b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf9948e5c51---sufuligusobedowodiragebub.pdf In PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c591f0249f2---38622408622.pdfIn PDF document text
    • http://ipublicity.cz/data/file/21137218987.pdfIn PDF document text
    • http://dycelife.com/userfiles/file/11922088690.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/kolujili.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/72a51e749f5fd1659ef5e3287fdbf055/gojimilu.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/wirude.pdfIn PDF document text
    • http://maciejabramowicz.pl/upload/files/file/45823164743.pdfIn PDF document text
    • http://snotlicker.com/clients/10243/File/zekagofizotefugesipawad.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/cbbbdc56bf5e0594a833a2d572ce2de3/16151258620.pdfIn PDF document text
    • http://kolkandkolkdesign.com/site/data/ws/files/27496648751.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/ribilolo.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/1fc0536133ec5cec6366ff78c64d66ef/51863936042.pdfIn PDF document text
    • https://procogs.com/FCKeditor/file/fojezevikexitosi.pdfIn PDF document text
    • http://b-solutions.net/userfiles/file/defubawojugetobarotet.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/2827852630.pdfIn PDF document text
    • https://vinaconexmec.vn/uploads/news_file/70278762213.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607533c6ed238---57742808472.pdfIn PDF document text
    • http://alconburyreunion.com/clients/36523/File/83558727041.pdfIn PDF document text
    • http://seowonbattery.com/files/fckeditor/file/221602058611ad991bc0ca.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0f23baf29b8e078b4dc9653b5cdf4d92/bipumadupomajiju.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/e937b0829c38a5a62f6491c69f328960/femimokosa.pdfIn PDF document text
    • http://gazdalkodjokosan.hu/img/userfiles/file/diwerapofivavorebosafazum.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/e6c17e3f893f9a952bcf01748692c669/suxopuxetefif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=area+of+a+circle+differentiated+worksheet+tesPDF 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_off0000e6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000febc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBC 17576 bytes
SHA-256: ca22948ab79b3769b7b165b18c901ac766ce080303bddfd90aa6a465f9420eb7
font_02_sfnt_off00012c36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C36 10732 bytes
SHA-256: 14304f3cac32db6bda2eedf6d3b2c45562b4dcb0c172ce2c4a03d1c83aaf82e4

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