Malicious PDF — malware analysis report

Static analysis result for SHA-256 104a3161db9856e9…

MALICIOUS

PDF

93.7 KB Created: 2021-10-06 07:31:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c6b01d6faba8e2937f51b799978a7080 SHA-1: ca3c20a165fafe44c4560567de007b0d363e9c61 SHA-256: 104a3161db9856e9b50a80a95f00d0b610b3410077fe3562d9579d66f7324a2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is used as a lure to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://coretry.ru/uplcv?utm_term=how+to+combine+multiple+pdfs+on+mac PDF link annotation
    • http://francescofesta.it/userfiles/files/92769676304.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/26711368782.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/vokigo.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/35330576156.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/xafavel.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/54022237786.pdfIn PDF document text
    • https://careerexpo.alljobsinliberia.com/ckfinder/userfiles/files/xukej.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/56c12b28b5acff7204f3ce1dc55202e4/lomeredegupo.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/fovagisezekugeborabewe.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c50ba4e8de---muxumuwaru.pdfIn PDF document text
    • http://nataliashishkina.com/userfiles/file/xunuwixazi.pdfIn PDF document text
    • https://olterus.org/contents/files/nurotowafekodibeb.pdfIn PDF document text
    • http://rabotatver.ru/userfiles/admin/937656296.pdfIn PDF document text
    • http://nova-auto.com/upload/pajanuvubadani.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/pawagijotogiwi.pdfIn PDF document text
    • http://lovec.bg/root/ckfinder/userfiles/files/lomelexeseropam.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/68883551883.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/6eb0c211b349900d26cb535c95d2ae32/doroteruzij.pdfIn PDF document text
    • http://wildzipper.com/clients/wildzipper/userfiles/file/rejunotumefejuf.pdfIn PDF document text
    • http://quartierdete.fr/uploads/fckeditor/file/fesofanonewiponenujisodo.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/13784347415.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/e00f6ec1a103dc33b8b12014a2710630/79066827623.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_off00010279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10279 20620 bytes
SHA-256: 627f501f4958847a314c00c528bad73f6dd0edb402c2e75f958eab541bcd7596
font_01_sfnt_off0001385e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1385E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15075 10996 bytes
SHA-256: dd59e75be88d972d4c471c112d11ad940b9ba1ce5c2277b32021f06d7f38e865