Malicious PDF — malware analysis report

Static analysis result for SHA-256 53ec5e7591e18e81…

MALICIOUS

PDF

77.7 KB Created: 2021-09-05 14:15:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 54c6fa5fcf452adbe5de6d56ddd932d6 SHA-1: 73e742fe76a06d445fe3477d877136b02a70eaf4 SHA-256: 53ec5e7591e18e816272391ae41b28f811312b31f950a210dd3a6a8d2d2d8af3
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple compromised websites, many of which host other PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF links on compromised CMS uploads suggests a coordinated effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://asupuro.com/user_data/image//file/dalugamovajitenarujex.pdf In PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16075f00d31a47---83851683593.pdfIn PDF document text
    • http://bogelaipigeon.com/upload/file/jopojebusamurarajejaw.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/69705727303.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/105fh1r2cn5gqi0b6s8639c3e2/33509631359.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160e79d1622fb3---zuxidikim.pdfIn PDF document text
    • https://educhina.mn/editor/files/xurago.pdfIn PDF document text
    • http://arredamenticucinesiciliane.it/userfiles/files/xewivogimupejisega.pdfIn PDF document text
    • http://tktravel.shop/FileData/ckfinder/files/20210715_453BAB3005EC7869.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af58818f3ae---vikiropexevumozusid.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ead38f2a51---67269050547.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/97934176664.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/3tlj3bs3d0dift0fceoi561fli/togodiwijaf.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/fowagiredikefo.pdfIn PDF document text
    • https://www.aeap.com.br/ckfinder/userfiles/files/17615701552.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/1841606224.pdfIn PDF document text
    • http://zussobrance.sk/grafika/dokumenty/60356443092.pdfIn PDF document text
    • http://orthocarecentroortopedico.it/userfiles/files/nuxuvamunudesiserajemig.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/noxobuwileroxixamasele.pdfIn PDF document text
    • http://lnimeina.it/userfiles/files/nuxabojixaroguzowop.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/63938059055.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=algebra+exponents+worksheet+with+answersPDF 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_off0000cbb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB8 16776 bytes
SHA-256: 53be0a577948cb4c1f93e16a2a56fe4f48c4af13a60a998146e8b82f3bba6ca9
font_01_sfnt_off0000f649.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF649 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E60 10932 bytes
SHA-256: bb4a0ec4f4feada2f4078322738a894c97258c6207fb2bae177a160c2998481b