Malicious PDF — malware analysis report

Static analysis result for SHA-256 564b418c5df1c3fd…

MALICIOUS

PDF

73.4 KB Created: 2021-09-20 00:08:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: feba138af9591ed843c805a6576759c3 SHA-1: 7f401e28ea53032d33c6d1b08b90de2a614981e7 SHA-256: 564b418c5df1c3fd165ca269e619fdfd90486bc0864cd9bcd84deb8fc2f4c71b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to external websites, including those hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or to distribute further malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/dekuvo.pdf In PDF document text
    • https://codecs.ro/images/file/patixesuw.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/kusupaw.pdfIn PDF document text
    • https://nullemont.fr/nullemont/ckfinder/userfiles/files/zogoni.pdfIn PDF document text
    • https://led7.ru/file/30617550671.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/39917724249.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/gumobuziguwogu.pdfIn PDF document text
    • http://emblem4home.com/UserFiles/Member/File/70877650146.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/79465870201.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/xados.pdfIn PDF document text
    • http://ore-processing.ru/d/files/43655461004.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/wegoxupurakepopa.pdfIn PDF document text
    • https://eownauto.com/uploadpic/files/70290332889.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/gulikitijomotujabuxi.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/h027mr62fom4imra68073r6c6i/lipapixatagakeg.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4142755d1---zubizipodutomit.pdfIn PDF document text
    • http://www.addvanceo.info/userfiles/files/31794275951.pdfIn PDF document text
    • https://sharks-cz.cz/images/file/zofimonewonugetel.pdfIn PDF document text
    • https://eltechma.com/zdjecia/fck/file/49392363650.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file///42130874159.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/161358959b78de---56477721924.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/52423131529.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=2+letter+words+starting+with+wPDF 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_off0000bad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAD2 10636 bytes
SHA-256: de2be9132e5331a9f3b074108eb6eb3cb781017dee285df2c4e62c314959dfa3
font_01_sfnt_off0000d2fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0D 17240 bytes
SHA-256: 5e4bb0b48c2ae53c6f1d148ce91a7da607fdf2f44bfee93f74a881fa041f6323