Malicious PDF — malware analysis report

Static analysis result for SHA-256 f52cae952d3539e2…

MALICIOUS

PDF

133.5 KB Created: 2021-08-07 03:10:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d7c1fe66ea1bc5db18955fd29f08cc7b SHA-1: e43f83e8dfbfc2765283d35b48b21abd390bd1ef SHA-256: f52cae952d3539e2e05660e2078cc7119f139d08e36b84d9966dca0ae8d4ae67
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised or disposable hosting domains, suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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
  • 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://tuzvedo.hu/elemek/file/nozutupufixirogu.pdf In PDF document text
    • https://devismesport.fr/userfiles/file/repivodefawizejujom.pdfIn PDF document text
    • https://verandapattaya.com/userfiles/files/gijufimudupu.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afc7389f657---tetunixa.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/67365014938.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2eea505409---gajafufumizeser.pdfIn PDF document text
    • http://coffee33.ru/archive/file/23960642404.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/19147568635.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2490c54b10---giwitolozomusodetus.pdfIn PDF document text
    • http://tatennis.ca/clients/29257/File/jejevebetul.pdfIn PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/guxapifarazadajopudesefu.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/d21510d7bb9bab782c18721b81a0cfcb/44490645817.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/8f8cb625fc61d3196789d36f106fa8f0/26601682804.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/03c635f13ff0bb86efe5304b402c0812/fabenagewar.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/103626d2d6b9759287cb865ea9ce9ba4/ratizukaruligigoru.pdfIn PDF document text
    • http://yunnanyingxiang.com/ckfinder/userfiles/files/puromifuxobuva.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b85ea0f0103---fatapugadi.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/nigunasugugudodawisi.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/eba2f8b7c45bf791098a494e148ddbdb/kalavewetepokidugotegeno.pdfIn PDF document text
    • http://rld-carbon.ru/file/sekutobu.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/zanesixebuzekow.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/74c3e01d5ea06faaa71b8b663a56e079/45084451655.pdfIn PDF document text
    • http://nowyhotelik.pl/userfiles/file/11220187741.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/nupatodaxupirudabujop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=esl+reading+comprehension+activities+for+middle+schoolPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/2bd93522abf2bde7b5c9ec62c93051eb/vifezedopuzoj.pdfIn PDF document text
    • 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_off0001a4bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A4BD 17812 bytes
SHA-256: e43f8fdfb4b1b1c0061c7bfecd208f74f79009dd452b5fc504b67abbdcaa6881
font_01_sfnt_off0001d3ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D3AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001ebc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1EBC5 11116 bytes
SHA-256: 32bdc9105f0788fb5871a827aed273dc14b6be88fbe270582aefb3987ba8e945