Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6a964d5b4660bed…

MALICIOUS

PDF

71.5 KB Created: 2021-10-09 20:13:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 413efb075c84b425a57d61cd1b09bdbd SHA-1: 297afc1d31be935603f8741a68b4bd8a969013d8 SHA-256: c6a964d5b4660bed08e9df9bc07b4c7e12c743b48d19047285c223b46a7b7cbc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains a large number of external URIs and links to compromised WordPress upload storage, suggesting it is part of a link farm designed to redirect users to malicious sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://krisoc.ru/uplcv?utm_term=dragons+of+the+edge+download+apk PDF link annotation
    • http://diplomat2014.ru/ckfinder/userfiles/files/75850865442.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140e37c33dc6---37127944920.pdfIn PDF document text
    • http://marcus-1.com/FileData/ckfinder/files/20210922_B7F098FD26A929BC.pdfIn PDF document text
    • http://suma.ca/upload/editor/file/welajuda.pdfIn PDF document text
    • https://camphacement.vn/upload/files/15980906098.pdfIn PDF document text
    • http://toflight.mobi/attachment/ckeditor/files/9f2c1e1ea5be389cca1138deebeaf9ee.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/nixivulupasiwopep.pdfIn PDF document text
    • http://inwallendorf.de/userfiles/file/fuposozonomavegesodusa.pdfIn PDF document text
    • https://bleikss.com/userfiles/file/geliluzetikimesof.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/98337508554.pdfIn PDF document text
    • https://tenderdiary.com/ckfinder/userfiles/files/wujexumugosobapese.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/65548406269.pdfIn PDF document text
    • https://ccskin.com/geektic/files/xofufotitotegimujibenoxos.pdfIn PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210924_055817.pdfIn PDF document text
    • http://erodiertechnik-wenzel.de/userfiles/file/20314791612.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16158a018cc155---xebom.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/bogiwugubavozobelajad.pdfIn PDF document text
    • http://goldendazzle.com/upload/quangtri/files/56949422194.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210918_BBB2E29F83282170.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/161500d808fcc9---81597922413.pdfIn PDF document text
    • http://agriturismolescuderie.eu/userfiles/files/tilimuxek.pdfIn PDF document text
    • https://gianlucabruno.it/dati/upload/file/7214969197.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_off0000b3b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3B5 17048 bytes
SHA-256: 153a9b0614141df0a958b0179d97792902cc0ba31b79d14047af1327db8ea089
font_01_sfnt_off0000df6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f782.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF782 10864 bytes
SHA-256: 80123344e0e1f25f53d793609978f6e4cd5deef789a1455144fd130e0ae12f3f