Malicious PDF — malware analysis report

Static analysis result for SHA-256 df8df615dd43ed22…

MALICIOUS

PDF

74.1 KB Created: 2021-09-07 04:29:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e2541ab3b9ce7beaa395c86f376f19a2 SHA-1: f4ac8efbba611dde93965bc45b42ac38116d580d SHA-256: df8df615dd43ed22a9215491bcd971825d469a07029136e4fc2e2ca875fb3820
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URI heuristics and the sheer volume of links indicate a strong intent to lead users off-site, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://chcial.ru/uplcv?utm_term=polarization+of+dielectric+material+pdf PDF link annotation
    • http://medicalproduct.hu/images/files/nekozip.pdfIn PDF document text
    • http://bowenlawmt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/15489476582.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b0c25b182---petatedatek.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/modeje.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/pujisedusaxutigofibik.pdfIn PDF document text
    • http://photou.cc//ckfinder/userfiles/files/rejazuvalo.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16116e496d63a3---18439266829.pdfIn PDF document text
    • http://longthinhphat.net/uploads/files/15483480791.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1f3efa9c29---nuwumilevepira.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/xobukulasolaxawidadixamag.pdfIn PDF document text
    • http://wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/82103667201.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/loxoxizumezatepez.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/90368753798.pdfIn PDF document text
    • https://proxus.nl/file/43890823532.pdfIn PDF document text
    • https://dampinggame.com/calisma2/files/uploads/welezadiw.pdfIn PDF document text
    • http://tafgambiatours.com/userfiles/file/66960685881.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161310e5e438d3---44433293401.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/75564928020.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a825c8ea7cd---81538461574.pdfIn PDF document text
    • http://pkynfe.net/userfiles/file/dusemepa.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/a69b9d3c421f9fa10d899512bd69e708/1093323015.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/12a3ba909962c60eb7b7f676a225710c/xubifot.pdfIn PDF document text
    • https://camping-du-lac-dijon.com/fichiers/25925992296.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/16418501679.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/d29f4d9bfedda8ed6f219f71cf16ee29/gigafuwupepuvako.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_off0000c1e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FE 10672 bytes
SHA-256: 5decdf6fa4418a26b96870e87ef0786783490e64d835b520b168677f3b513ec5
font_02_sfnt_off0000f26f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF26F 15612 bytes
SHA-256: bf8f54faf4c070662ac74d7d92ec101a573b6b11972003f0c1c30a8852dff403