Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c91f721dbee709…

MALICIOUS

PDF

99.1 KB Created: 2021-06-21 19:24:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 9d97657955a6ee8c7b34312bcaba8551 SHA-1: e97141c2f8d49c5abcbe2b702cf15058b4551eaa SHA-256: a5c91f721dbee7095a8713dddecdda7a61d779aa11d368469026d355a3995589
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links pointing to potentially compromised WordPress sites, suggesting it is part of a link farm designed to distribute malware. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains text related to a search query for a PDF solutions manual, indicating a lure.

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 https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/rja9gblgs0qf6q2cs1c5t5qjil/85163367911.pdf In PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd050dd696---84680084344.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a76b2358d---fepabo.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/68f2747147b07f9f166052b71ccabe4b/6540912709.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/samivefizovagakopibuxuke.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3d2b5c105---kuzotufi.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/nepevidetiwa.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/29af06bdcdc37ad67cecb55179766792/39827148972.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/nfkfthpug4srge7q15dcftkvl9/49084607322.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/539bb59cab599a47842f4ebd76047b44/povavoso.pdfIn PDF document text
    • http://vaikevai.com/ckfinder/userfiles/files/vosejomujasug.pdfIn PDF document text
    • http://marinapogon.pl/upload/file/51590487017.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160841d686b54c---16455962822.pdfIn PDF document text
    • https://cape-electronics.com/media/file/29283447323.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/dusalabirebesimerejiwuve.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/s8qfthfhbf04o35e460smobc99/kezefuvudipovivuvuw.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1e8d7c2c17---tifubanijugawabi.pdfIn PDF document text
    • http://dentherapia.hu/files/file/81589051734.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/LPIa9PGmDLg/uplcv?utm_term=digital+design+morris+mano+5th+edition+solutions+pdf+free+downloadPDF 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00015f65.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x15F65 18292 bytes
SHA-256: ea0c1d2c4e6bbafeeebc4298a0447ae50a79faddae43a8fce19007d6e807fa9c
font_00_sfnt_off00012379.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12379 5672 bytes
SHA-256: 9d75298f1ea164ebe177a496a00714ebed78d2063637ca55e15be51b3b6c6210
font_01_sfnt_off000136b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136B6 11784 bytes
SHA-256: 41746fd5461e2d0dd4cf2f8ab102b7f29bdef77cc062f7d46cbd7e776369a53e

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