Malicious PDF — malware analysis report

Static analysis result for SHA-256 50d3f6812357877c…

MALICIOUS

PDF

68.4 KB Created: 2021-02-22 04:19:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f4f16964201b9081807b919e9ad63482 SHA-1: b245d5feb13bc09c9060cc8927892b725d1b752f SHA-256: 50d3f6812357877c2eadd9da8e24dcae28a990554ba322cd832c3ddf01b9052e
194 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.001 Process Injection T1204.002 Malicious Link

The PDF contains a critical heuristic firing indicating it links to known malicious redirector infrastructure. The ML classifier also strongly flagged this PDF as malicious. The embedded URL is a redirector likely leading to a phishing page, as suggested by the SEO UTM parameter in the URL. No scripts were extracted, and the document body was heavily obfuscated and unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://crophysi.ru/strik?utm_term=how+to+read+book+summary In PDF document text
    • https://static.s123-cdn-static.com/uploads/4478683/normal_5fc9458c5c84b.pdfIn PDF document text
    • https://cdn.sqhk.co/nupegefozub/qQjgtgn/vubobogapu.pdfIn PDF document text
    • http://zesigosaf.22web.org/is_there_a_spreadsheet_app_for_iphone.pdfIn PDF document text
    • http://rebituzugofebo.22web.org/vyapam_jail_prahari_admit_card.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413240/normal_601b7b5336304.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jepevam.rf.gd/what_is_the_function_of_law_enforcement_in_the_society.pdfIn PDF document text
    • http://rewogaki.rf.gd/citroen_c4_picasso_2007_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/fevobelijogal/android_tv_6._0_rom.pdfIn PDF document text
    • https://s3.amazonaws.com/xojafemori/jenuxazipow.pdfIn PDF document text
    • http://jigosip.epizy.com/macroeconomics_exercises_with_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/sajatofubote/41004371271.pdfIn PDF document text
    • http://jazupizewatabal.epizy.com/pijupo.pdfIn PDF document text
    • https://s3.amazonaws.com/winumigutam/22894544702.pdfIn PDF document text
    • http://ripazek.epizy.com/berutobusazekuxadubenaki.pdfIn PDF document text
    • http://fepoxojosatomu.epizy.com/bsplayer_free_windows_7_32_bit.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_off0000d0cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0CD 5296 bytes
SHA-256: 4be5fdd6d450ac62d88ed7da26902da729613d3d8fba03986d1f3a9484d73f00
font_01_sfnt_off0000e2c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C8 9976 bytes
SHA-256: fd0999eea4eb88bc201fd5e8f2655a0d108828100854bf512189dd1c87d062ca

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