Malicious PDF — malware analysis report

Static analysis result for SHA-256 c904ddc34f772e2c…

MALICIOUS

PDF

84.7 KB Created: 2021-10-09 08:01:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7e91c32bf9ea229598a7210ceb35616b SHA-1: 174ad2669ef7058c3d8c632dfceeee73b69e7e08 SHA-256: c904ddc34f772e2c59e1d953a4b3c15088489ffc71c3af54c08328bdef38d95d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. The heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on various domains. One URL, http://www.520amis.com/upload/files/82132963380.pdf, is identified as a potential distribution point for further malicious content. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest an attempt to exploit document viewers or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • 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 http://www.520amis.com/upload/files/82132963380.pdf In PDF document text
    • http://gt-outillages.fr/ressource/site-image/files/nakugugalelesene.pdfIn PDF document text
    • http://stagticket.com/fck_upload/file/sipenazuvisedepasizogo.pdfIn PDF document text
    • http://jimsclub.net/new/board/img_tinfo/file/20210902000314.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/xiwomowexiresobogosem.pdfIn PDF document text
    • http://matraholding.hu/images/userfiles/files/59923405413.pdfIn PDF document text
    • https://jungleflightchiangmai.com/Uploads/files/86560810449.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd5db3989e---jesukomuzafedoto.pdfIn PDF document text
    • http://aalzkj.love-mrt.com/upload/files/60196444380.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210927110510_686151605.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/28357588859.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/fetuwavunujitonatun.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109222017184133.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/52180648090.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/xogodozutodobazevowutami.pdfIn PDF document text
    • https://kmedebiyatgunleri.com/ckfinder/userfiles/files/xipijelubojaka.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/57125216609.pdfIn PDF document text
    • http://capri.lt/userfiles/files/tajeleterovajile.pdfIn PDF document text
    • http://inica.org/files/file///zigofebigiripagotumax.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/ratip.pdfIn PDF document text
    • https://soechi.net/userfiles/file/35742064517.pdfIn PDF document text
    • http://newcityhk.com/userfiles/pisebapuxarigelirux.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021100521053073499.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=how+long+do+african+land+snails+livePDF 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_off0000e805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE805 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001001c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1001C 10696 bytes
SHA-256: ae6b813eca05ae99f140bbbe59f982f4401a2753fc33d819165c4599c51cd414
font_02_sfnt_off00011890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11890 17608 bytes
SHA-256: 6c0a4077cda0b37b1e37207a2eec9f150dbb9760670a3209d6e6fbfcbcc58f84