Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c1a6e4b93da3288…

MALICIOUS

PDF

93.0 KB Created: 2021-10-10 11:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 833a9e2936e542099c305b4e8c37c0b4 SHA-1: 141c78b4d5768c2f9a2035c5f8a075fdb1c8ed96 SHA-256: 7c1a6e4b93da32880f607bc079c0ad8934df2d26d1059e266d06d904fd3fda6b
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct textual lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://pixomot.ru/uplcv?utm_term=57+minute+timer PDF link annotation
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f397f0b588---69439425657.pdfIn PDF document text
    • http://luligang.com/ckfinder/userfiles/files/dumubejofofodube.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/38838341806.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/sedeg.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/121c3619f883811d1912182bf835dc86/xemuduzozijuzifelazid.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/tojalowuvewelazo.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/xopufijido.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/38122562181.pdfIn PDF document text
    • http://epmachine.ru/d/files/levoxobojexamula.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/gerarotupoboxekofapur.pdfIn PDF document text
    • http://bjjiffy.com/upload/74353134606.pdfIn PDF document text
    • http://simsvizag.com/admin/uploadedfiles/file///14739366966.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/vopuposoxibowasode.pdfIn PDF document text
    • http://www.petercar0937494634.com/upload/img/files/41947127132.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/kaifhdq405jhbatm65fcnmo1ve/53401086275.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615fe61cc3900---konoka.pdfIn PDF document text
    • http://anoh.net/pds/userfiles/files/93222399734.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/93503661031.pdfIn PDF document text
    • http://fkm-lux.by/var/upload/file/64854060251.pdfIn PDF document text
    • http://congluc.com/upload/files/bawogigosoliwupane.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/dixamelesu.pdfIn PDF document text
    • http://infinivideo.hu/sites/infinivideo/files/66532748927.pdfIn PDF document text
    • http://henzefashion.com/userfiles/file/20978510460.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/83828173794.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_off0001040f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1040F 9960 bytes
SHA-256: cdb46da034af40e6dafe21c08d77e942b36eb6cc73fce02629f7eedce4cd4865
font_01_sfnt_off00011a10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A10 20048 bytes
SHA-256: 2018da7aaf661277c105d9815f11a5efc3db1aaf01cfadfbbcbe58a52145afd0
font_02_sfnt_off00014ec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1