Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1259e8929e49cf6…

MALICIOUS

PDF

82.0 KB Created: 2021-09-06 17:29:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f86f1095babbe224fb347311a3ca8a3b SHA-1: 1a17d7524a564f1dde8d512c96b03d2fa6566af8 SHA-256: c1259e8929e49cf6539f73c845736cf4c4afd8c1b0f0f82e035b1971020cbc4d
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external resources, many of which are hosted on compromised WordPress sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to deliver a secondary payload or phishing content. The presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the malicious nature of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16071bfaad379e---kakunidoge.pdf In PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d7b810fa8---wepositogepupimebubem.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/48fe7901ee3d80b9848800d3b5f4587b/wejigufezixiliwawafanu.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c20399d0d4---finugej.pdfIn PDF document text
    • https://by-express.com/upfiles/editor/files/zulosakabidap.pdfIn PDF document text
    • http://emmanuelmissionarybaptist.com/clients/74938/File/nigupex.pdfIn PDF document text
    • https://emauto.lv/index/images/up/file/zotomatimip.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/pudok.pdfIn PDF document text
    • http://smcertificationservices.com/userfiles/files/99003919685.pdfIn PDF document text
    • https://intellicapital.in/ckfinder/userfiles/files/kefatuzin.pdfIn PDF document text
    • http://frankifoto.com/uploads/pages/files/57140805808.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/rudevok.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609867f5782a0---15395860858.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/5ad0a139206967dee2432dfe313f04a8/35666900753.pdfIn PDF document text
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/ebbb37a51bb2648407f2c25cb5b22d4e/51896031869.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/42123815205.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/da7af8c59daab656b46ee5773f7541c9/mamedusowubil.pdfIn PDF document text
    • http://vietthanhstone.com/images/news/file/zubebenowobilamokawi.pdfIn PDF document text
    • http://groupementpecheduloir.com/ckfinder/userfiles/files/28706762147.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1608354b032c26---xunin.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16070c1451c8a8---sezemiduvofazebuvajekame.pdfIn PDF document text
    • https://ayurvedaemart.com/uploads/file/43418910289.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098401ff24e2---78713301678.pdfIn PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/53208305754.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=imagemagick+convert+pdf+to+tiff+command+linePDF 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_off0000d95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95D 18256 bytes
SHA-256: 578afc86fb65a72de0579462d3b4a8daf6fc43435efdeb0eb030960a56061275
font_01_sfnt_off00010878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10878 10904 bytes
SHA-256: 351faf861cfb9f760ddd3c7f614e54cb0eac9c4d1ba7a87bea05e9bb5fc10ac6
font_02_sfnt_off00012181.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12181 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1