Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c4e23653ef9f138…

MALICIOUS

PDF

85.1 KB Created: 2021-09-19 22:05:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7b3eb131469ddc414bc4621d2ae8e68b SHA-1: f56040fa65385c0e5d081de6e695ca0bc1112fa2 SHA-256: 4c4e23653ef9f138f45b550818b747152bb051d98eaa0fbd33187c3a306ee0fa
134 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous embedded links and a heuristic for a 'download button' suggests a phishing or malware distribution lure. The document body is heavily obfuscated, preventing a clear understanding of its specific content, but the overall structure points to a malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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
  • 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://bisleriuber.genefied.co/ckfinder/userfiles/files/livozilikotalerutanimip.pdf In PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/77027718648.pdfIn PDF document text
    • http://cjpharmtech.com/upload/files/binujawapo.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202109091014506960.pdfIn PDF document text
    • https://tiemhoamo.tiemhoahaibara.com/data/dulieu/files/sozawibazidop.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/dotodikamevifozurikige.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/8896241380.pdfIn PDF document text
    • http://geometramaurotozzi.it/userfiles/files/remugegotepakupup.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/30427793392.pdfIn PDF document text
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/1004936722.pdfIn PDF document text
    • http://kamakuralosgatos.com/uploads/files/81464271660.pdfIn PDF document text
    • https://yensaovinastar.com/media/files/34645361088.pdfIn PDF document text
    • http://dallard.fr/ressource/site-image/files/55701162858.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/terabanogirefokeli.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/1364678030.pdfIn PDF document text
    • http://homokkepek.hu/editor_up/98722120497.pdfIn PDF document text
    • http://frchem.cn/upload/files/sinuxozuwelalujilogixefeg.pdfIn PDF document text
    • http://storemisr.com/uploads/files/xuvofijasumubume.pdfIn PDF document text
    • http://hoclaixebinhthuan.com/upload/contentFile/file/pirogim.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/dizubolujizasevonevijune.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161369ba697c95---34731585692.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/xupiguj.pdfIn PDF document text
    • https://ppuhperspektywa.pl/files/edytor/file/94699254432.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db36e90f1a---nuwudabemekogifol.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210901072517.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=new+imoba+app+apkPDF 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_off0000e573.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE573 19240 bytes
SHA-256: fe603268c227c104420445e7c6250425db36d64ffb3845e553c3c97366d45e84
font_01_sfnt_off000117ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012fe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FE1 10192 bytes
SHA-256: 8a28ddb9df3e4313032b663cb020eed60f2ef3e4807e553f4f6c7987971c2398