Malicious PDF — malware analysis report

Static analysis result for SHA-256 f931abcc71857c4c…

MALICIOUS

PDF

75.3 KB Created: 2021-09-08 13:04:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: fe5cba15b1380141d4544b91392e0978 SHA-1: 3631d3bff58d4bf9c716132f1e78f0d3fead5678 SHA-256: f931abcc71857c4c490690e0cc326ab06af1f501aeb7d8c7de841043ee1578d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and the overall structure indicate an attempt to lure users to external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ketchas.ru/uplcv?utm_term=linking+verbs+worksheet+with+answer+key PDF link annotation
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/rm2vj0sbga48qhidamdmu2i9vp/tufuwolalazupumovipide.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/xobijado.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/wipuwemawizojeniboge.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/3a9dd50af7da126d6dcbc7523a045ecf/34649461085.pdfIn PDF document text
    • http://aotem.com/data/home/qxu1780220113/htdocs/uploadfile/files/guriginijasoxisu.pdfIn PDF document text
    • https://thediamangroup.com/_images/files/suwibumeni.pdfIn PDF document text
    • http://thanhtindesign.vn/uploads/image/files/rilewovefuzakip.pdfIn PDF document text
    • http://hbaoge.com/upload/files/21007316221.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/fovupisoriwawerawob.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/71012622988.pdfIn PDF document text
    • http://dawahcity.com/userfiles/file/jolovusuxerebe.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/gazajufujawijon.pdfIn PDF document text
    • http://zzquansu.cn/d/files/16831509936.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/75918466825.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/g4rrd19t77mcvmcoteou0rp9cg/tidalo.pdfIn PDF document text
    • https://mashtalkandil.com/userfiles/file/90239552314.pdfIn PDF document text
    • http://adwokaci-pila.pl/userfiles/file/56924381044.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/repigegozavana.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134f149b27f5---54277378357.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/3901242085.pdfIn PDF document text
    • https://people11people.gr/uploads/File/49192064140.pdfIn PDF document text
    • http://unseenadventure.com/userfiles/file/26961480835.pdfIn PDF document text
    • https://olboihorgaszto.hu/editor_up2/13193590917.pdfIn PDF document text
    • http://pantanalmsnews.com.br/ckfinder/userfiles/files/latirebas.pdfIn 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://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_off0000c439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC439 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC50 10796 bytes
SHA-256: 67f71d2fa768c7df8b947f7b90287bd6ed91e0ca0c4a3d74819ec7fd0ceb313d
font_02_sfnt_off0000f538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF538 16388 bytes
SHA-256: cafbe06b6b25172107e960de964b5b93a74d40794e900acaebdbe7257f50deaa