Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f40ef91eb8ef83d…

MALICIOUS

PDF

76.3 KB Created: 2021-06-20 03:11:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: e8b7896f5a41d8dc37b2a299c20a5a23 SHA-1: 4969932fd8309b899ea5361901b19a88c929b8bb SHA-256: 5f40ef91eb8ef83d7077cd96dcf3fc9a43cb069dc534a67746989f9c0e29a3a6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm or phishing attempt. The document body, though heavily obfuscated, suggests a lure related to IELTS letter formats, likely to trick users into visiting these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jumuwebisunoxu.pdf In PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/6ae60ng01nn6m6srha93uhl370/vanemusapirup.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098a7011203c---33754713964.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094639a4db0c---13854499165.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/zizulimatudajalinutet.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/vatogetisidilujalafozagor.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0f3d4348e---letew.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/talorewekuj.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8f9bac2f2---32686541685.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160ae16e5dcc04---65756454719.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/sst4n1ocdc4c91i9fn9f879cfa/tidaliletaj.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/74745366760.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/50f6b9d89eeac56875ab2fc6c2320f86/31141248567.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/xepejigujoxov.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=letter+format+ieltsPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e40e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40E 4856 bytes
SHA-256: 78ad221e413e46eadcbc06ef778a396381157db10bc1dc854daf9b6e4bda1763
font_01_sfnt_off0000f46f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF46F 2252 bytes
SHA-256: f3ffe4ba3621d765656d78aaabd71fd798feab98c1821a744cf45e925a576ee8
font_02_sfnt_off0000feb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEB0 11060 bytes
SHA-256: 39d64f9c8eab5d2cf7db81a924769e11b02fa1a5e1d178b520bc333efb182258