Malicious PDF — malware analysis report

Static analysis result for SHA-256 efb50b4a7d3bcbb1…

MALICIOUS

PDF

81.0 KB Created: 2021-09-05 04:31:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: fd0f6958d053d677d2d057fd0abb1c33 SHA-1: b26e4cf1adb427c73f2280bca95e0736049e03e1 SHA-256: efb50b4a7d3bcbb12e8d9d224e5d8cac8d815c70421eceae991ff439400e434e
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites. The presence of numerous PDF links and the use of compromised CMS upload storage suggest an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.yemany.com/yemfiles/files/85110073404.pdf In PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/10357597523.pdfIn PDF document text
    • https://cristalensi.com/public/File/xubatevefoserik.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c6ed9833436---jumovarivavavob.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/guwutukifewivepikesuza.pdfIn PDF document text
    • http://hhoasis.org/app/webroot/img/fck/file/11480279695.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/be10459d107be5f4ce0822e1a2434f2a/fufogedup.pdfIn PDF document text
    • https://martabaktelor.com/contents//files/sudomubinigasibor.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/44e807acb0ce83e4c82add0e9710ce9e/72727090186.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/kilanaxeronaga.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/6c3esnilmo07os2p8anvamuh5r/82121323999.pdfIn PDF document text
    • http://yogo110.com/userfiles/file/nuvimoderev.pdfIn PDF document text
    • http://www.vnos.vn/app/webroot/uploads/files/lugelux.pdfIn PDF document text
    • https://isosklo.cz./uploads/50927222963.pdfIn PDF document text
    • http://e-park.es/img/uploads/files/73712746702.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/bd57b7f886cbda9f5e4721e78250ec4a/rupan.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ec9d66014f3---19417153010.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612bb84a9f8a3---53549379743.pdfIn PDF document text
    • http://halaljones.com/uploads/files/gijosi.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/7beaf887b03bb1319416cedef84d5c8c/580728488.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=adobe+acrobat+pro+convert+scanned+pdf+to+textPDF 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_off0000d751.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD751 17612 bytes
SHA-256: 47b20d0657283863c9ca0a0c85c66a8416ac287e7e3aacd9ea74f607b67ae5d2
font_01_sfnt_off00010531.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10531 10764 bytes
SHA-256: 01341ca5ad47b789201aca50aa4d9322d550cfa2fb2f9f2fca70ff589f5df971
font_02_sfnt_off00011df2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1