Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0a28963e5e56634…

MALICIOUS

PDF

78.3 KB Created: 2021-06-11 23:48:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 48d3e71c09fb38bd63df310752b92add SHA-1: 32da6305200eb585aac6853f69bbb93f3f64b3eb SHA-256: c0a28963e5e56634683bf5fff7e021f1a7d9fe35bda6f13348b21f2fb10ed293
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm for phishing or malware distribution. The document body, though heavily obfuscated, appears to be a lure related to an academic solutions manual.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=principles+of+electronic+materials+and+devices+3rd+edition+solutions+manual+pdf PDF link annotation
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc35b8b968---kozolawupa.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/nufebu.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/c49fbc76102026ab27ab60eae065d338/11742012488.pdfIn PDF document text
    • http://bigandtallking.com/userfiles/file/wiganes.pdfIn PDF document text
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/160769522637cf---55501014883.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4141a3f59---goporomunemi.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/45608275d4c9bea50473b22d40d46a19/52372687951.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/te6r3je04ucdq809n4nc7gru85/rozixekekupimizen.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/1435006722.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/gawetomukofodidugolaxodex.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/p32sd5arifgbfv45fa62gb8gfm/23104457736.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a44bee810a4---juluwe.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/42328863390.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/a0eced48ca5ccd18b622853a83da782b/vewanikunoforoduviw.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16072484d496de---zagavekab.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/ee31aa6248eb9b636705ce0d26e5cdc0/86980349170.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16073d52600ce6---xugux.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0C8 5524 bytes
SHA-256: 9f3a1dbca30f00f1095236c6dad5d1778c8e7494893ee992712bee05c5ac37ac
font_01_sfnt_off00010384.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10384 11072 bytes
SHA-256: 98a913143942bda632f2ec84b18013901f6b9492816bb61dbca9de1696b4bd8d