Malicious PDF — malware analysis report

Static analysis result for SHA-256 c73ab3e1f1b3907e…

MALICIOUS

PDF

73.0 KB Created: 2021-01-12 11:42:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 3670781fa3ecda4a5ab795615e6341f6 SHA-1: bdbfbb45a692a23999a6d15694c3793ff09d34df SHA-256: c73ab3e1f1b3907e05ebfdfa1793118c3ffee92302cb97e63108b618519249b6
192 Risk Score

Malware Insights

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

The PDF contains multiple embedded URLs, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, suggests a lure related to academic materials, and the presence of a 'download button' heuristic reinforces a deceptive download attempt. The ML classifier strongly flagged this PDF as malicious, and ClamAV detected it as a phishing trojan.

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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://traffking.ru/aws?utm_term=jkbose+10+class+private+date+sheet+2018 In PDF document text
    • https://saletenabij.weebly.com/uploads/1/3/4/3/134339554/2105526.pdfIn PDF document text
    • https://cdn.sqhk.co/bifoligi/gijgjfH/32131566578.pdfIn PDF document text
    • https://cdn.sqhk.co/kavejufa/jcQMUie/mens_save_the_planet_vans.pdfIn PDF document text
    • https://site-1178100.mozfiles.com/files/1178100/daresizumulizosatarekazi.pdfIn PDF document text
    • https://site-1172173.mozfiles.com/files/1172173/sekasobanupamage.pdfIn PDF document text
    • https://cdn.sqhk.co/jivaduzar/giejhjh/gaminator_casino_slots_free_slot_machines_777.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426087/normal_5f99fb4831d54.pdfIn PDF document text
    • https://cdn.sqhk.co/rifusofuwedi/gggege7/go_fish_card_game_walmart.pdfIn PDF document text
    • https://site-1193774.mozfiles.com/files/1193774/rutimifiz.pdfIn PDF document text
    • https://cdn.sqhk.co/fujalapevame/igO1iiV/best_3d_archery_quiver.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383703/normal_5f9116c8ec4ee.pdfIn PDF document text
    • https://site-1166657.mozfiles.com/files/1166657/weather_radar_freeport_ny.pdfIn PDF document text
    • https://site-1171784.mozfiles.com/files/1171784/dhoom_2_trailer_video_hd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487184/normal_5fb59c74e3c9f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/dukexajuj/google_adwords_exam_study_guide.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD3 5932 bytes
SHA-256: 236d5897b512eb5ca99000487f620168aa198f93db769c88ab4569cac9fd9b6b
font_01_sfnt_off0000f400.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF400 10184 bytes
SHA-256: da3f2f237cd27b64fb68ec83bbe7ccdf11f6afe43c69fc2d4e7ee18e802602f0

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