Malicious PDF — malware analysis report

Static analysis result for SHA-256 f42e5db2372294d3…

MALICIOUS

PDF

73.4 KB Created: 2021-09-13 21:56:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ca9b927908c89a7e7592dc45ca8369a0 SHA-1: 48d304785f7d7950ed730643865721c59cdc2997 SHA-256: f42e5db2372294d33edd92578a4c2f6925edd38667479278fae130f897a2d40a
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs pointing to external sites, some of which are hosted on compromised CMS uploads or disposable domains. This pattern is commonly used for phishing or to redirect users to sites that host malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to obscure the true destination or host.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://iaestedresden.de/userfiles/file/99069427409.pdf In PDF document text
    • http://hyunsin.net/userfiles/file/katukovuwaba.pdfIn PDF document text
    • http://solee56.com/ckfinder/userfiles/files/69366296285.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/xarif.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/41954639634.pdfIn PDF document text
    • https://cgeminfos.ma/upload/file/xemizovapufedorarir.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/67192306345.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613720211f1aa---werilozixorupigalu.pdfIn PDF document text
    • http://medi-sen.com/files/files/wodosodarawuvetodap.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132c8b0af9db---38360213782.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/633f6ae1a82f2d2231860244dfbeeced/82628558662.pdfIn PDF document text
    • http://weddingdove.tw/uploads/files/202109060155514581.pdfIn PDF document text
    • https://alistairmills.com/ckfinder/userfiles/files/56009327445.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f980daf7ba---monamepenejevap.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/0f1f2a94ac183f1995c99fa1b3b34192/76880789281.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/03j476qhe6ffnqinkl2f2rko36/fomikefobijagidifutagupe.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/34775659366.pdfIn PDF document text
    • http://tochuchoinghi.org/files/13913253386.pdfIn PDF document text
    • https://24emk.ru/ckfinder/userfiles/files/sudasazukeponedu.pdfIn PDF document text
    • http://vidol.eu/userfiles/file/xumif.pdfIn PDF document text
    • http://hangtatmj.com/userfiles/zawekugonopagurovokukew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=navegador+predeterminado+androidPDF 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_off0000bd8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD8D 16488 bytes
SHA-256: 743337fb1dce9a840b60c11882987757ea8c4c0daeb683d27732167426e81cff
font_01_sfnt_off0000e7de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF5 10564 bytes
SHA-256: d722f0b4d760dcd04762f41b0c996410bfaa94f244b9383a8085aba508aede2e