Malicious PDF — malware analysis report

Static analysis result for SHA-256 11591bb8a9738bcf…

MALICIOUS

PDF

94.9 KB Created: 2021-08-05 02:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 26fa044b62a8ed93ae84fbe0b284d6b2 SHA-1: 4037f68c602363f83a530e6ac39886fafb17f356 SHA-256: 11591bb8a9738bcfb73e6a33611335939e2aa2510e873646d9441194b79e2e20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 http://bluestandard.pl/ckfinder/userfiles/files/48992441961.pdf In PDF document text
    • http://debnine.net/UserFiles/File/21681774810.pdfIn PDF document text
    • https://hirurgija.me//files/83620599922.pdfIn PDF document text
    • http://smartarts.bg/userfiles/file/xirikikad.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bcbf688a5---95066023908.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/7nuirn4vsp601jdq7v82jk7652/21532115658.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/37292020575.pdfIn PDF document text
    • http://angelofthewinds.org/ckfinder/userfiles/files/walata.pdfIn PDF document text
    • https://adasms.fr/userfiles/file/laxizizimonep.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/pawuwexan.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6b4006f272---firivepisamofuwufekesapa.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ee0d8103c---51501089226.pdfIn PDF document text
    • https://prestinireedcorp.com/userfiles/files/worikevujaxukokev.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16203469417638.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/numabomidigebeg.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/5215732679.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/gelozalejeviv.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3db812afb---wubufekewivor.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210722_FC7DD62D79B62290.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/0d8cba34fefa7b07b3b13c07da510f8a/piponatubun.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/58783978850.pdfIn PDF document text
    • http://stellarp.com/userfiles/files/paxoxopakexo.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/e93274e630a9dd07c3741f68c34c1c10/41794884981.pdfIn PDF document text
    • http://deleersnijder-bocaege.be/images/file/tiduros.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=age+of+war+2+hacked+unblocked+66PDF 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_off00010b88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B88 11084 bytes
SHA-256: b4fa57a4dae3ec0d6c410473b9b163f7cbd0b9eeaa57fb1a5e8f60bc54a9d8d0
font_01_sfnt_off00012542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12542 19296 bytes
SHA-256: 7228ed82715aa8ea9663854b03dbff7e593b750ae02cc575e62eb268eec0eb73
font_02_sfnt_off00015614.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15614 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1