Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d8b2b7fc2f58df…

MALICIOUS

PDF

68.8 KB Created: 2021-10-01 01:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c93f421f8197800294dada49a7d4cca5 SHA-1: 328506a37c17ecf4bff214fa3a3c6ce7d0eed76c SHA-256: 21d8b2b7fc2f58df3cf479a47e70ad0a7ea5337470ccefde96c607a77a005993
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a phishing lure due to its image-only nature and embedded action trigger, typical of screenshot lures. It contains numerous links to external PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to a malicious site or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://ntct-dz.com/ckfinder/userfiles/files/gadumedoviruzifibakasiwu.pdf In PDF document text
    • http://coaching-scolaire.net/userfiles/file/58518188169.pdfIn PDF document text
    • https://deverfgrossiercms.deindrukdemo.nl/upload/files/2601184694.pdfIn PDF document text
    • http://nofatrans-int.com/userfiles/file/57947449545.pdfIn PDF document text
    • https://rwd.webseo.tw/upload/files/51128214568.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/jaferabolazof.pdfIn PDF document text
    • http://dgxzz.com/uploadfile/file/lesarezipewiwopemef.pdfIn PDF document text
    • https://auto826.com/uploads/files/80757127087.pdfIn PDF document text
    • https://slavyansk.biz/userfiles/file/xegitefodiwena.pdfIn PDF document text
    • https://garraldaarquitectura.com/garralda_userfiles/files/74615282580.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/roxibinosebekar.pdfIn PDF document text
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/37044746841.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615636a6e0324---16391838404.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/tuwera.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/lovekizusade.pdfIn PDF document text
    • http://elitacasa.it/images/file/vebiguwovopuzi.pdfIn PDF document text
    • https://wcfkenzi.com/ckfinder/userfiles/files/werazomanibutazuvofotun.pdfIn PDF document text
    • https://acatay.daynexdemo.tk/upload/ckfinder/files/xusumuserusakumoxeset.pdfIn PDF document text
    • https://naves.cz/res/file/vufejotefelobefikit.pdfIn PDF document text
    • http://rockefellersgold.hu/editor_up/goresimejamudizitak.pdfIn PDF document text
    • http://dorapeyzaj.com/userfiles/file/21159727819.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/nufufoxovabulowovo.pdfIn PDF document text
    • http://poaglasses.com/uploads/files/202109061325084147.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/liremuxuwun.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/92610363311.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=return+to+the+36th+chamber+123moviesPDF 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_off0000b00c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB00C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c81e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC81E 14088 bytes
SHA-256: c0e52c3eeabc0becb7f00026feb030d4e3522d1c08e156182d604a5cd5a8ca19
font_02_sfnt_off0000eb12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB12 11312 bytes
SHA-256: 694a0c29d9e1ba1aa5acf8fc43379bbb6f58f1704c825e14ef8dccd159013e57