Malicious PDF — malware analysis report

Static analysis result for SHA-256 3840f16b1e5ac7a5…

MALICIOUS

PDF

83.4 KB Created: 2021-09-11 09:37:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 741cec9ff7a690b67fe9cd7320124b39 SHA-1: 61d58bfe4ff8c81fe256a463b8e5e1e6991ef882 SHA-256: 3840f16b1e5ac7a537428a1a38a60ca577314b0d4f4f4464f26aa267282e20ce
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common method for initiating malicious actions within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://catamma.ru/uplcv?utm_term=peak+pdf+book PDF link annotation
    • https://wietsevoermans.nl/ckfinder/userfiles/files/2262503167.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/73202465495.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/63203134309.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/93976036369.pdfIn PDF document text
    • https://jensbrode.de/files/file/56904689141.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c47cb51958---15328516577.pdfIn PDF document text
    • https://penzion-pod-rozhlednou.cz/img/file/5962380066.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/62692476652.pdfIn PDF document text
    • https://5ky13lu3-1251.com/contents/files/zapedivepofulosuxe.pdfIn PDF document text
    • http://hyundaiokla.com/uploads/files/96389548642.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/598c68c26b075c7293aa62432f6460e8/giwopadikugawuponakotogox.pdfIn PDF document text
    • http://machin.kr/userData/board/file/mazosifufapo.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161354ca2178e3---35253245325.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/webopikimi.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/52681699073.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/85555936620.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/xikinusimirixezi.pdfIn PDF document text
    • http://www.madiran-cruduparadis.fr/ckfinder/userfiles/files/46202614006.pdfIn PDF document text
    • https://lhorizon.ca/uploadHorizon/file/19757051856.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133ca05a48a9---jibevu.pdfIn PDF document text
    • http://healingtown.org/userData/board/file/zedejixulazupaja.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/zifovoxufozadov.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_off0000e1cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1CC 18284 bytes
SHA-256: fe4f78abdf9a43414c6594b66d255864125cc73d6feea56fe4ef6cbcbb52b624
font_01_sfnt_off0001117b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1117B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12992 10116 bytes
SHA-256: 28ad40498c045827dda98f31f80e0e4fedb58b9551f4b207d304853fd4601c31