Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f1ff7558296c59…

MALICIOUS

PDF

79.0 KB Created: 2021-09-19 14:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 188a5abfc408c6915670f3dc0d11d7fa SHA-1: 405370427fe209e2c585479d01a16afc684f92c7 SHA-256: a6f1ff7558296c5903e3f2acd481a186a7e50a610c44f8f23d183b5bea0ac527
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress upload storage 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. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7019

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://archism.ru/uplcv?utm_term=check+touch+screen+android+code PDF link annotation
    • http://eventechsite.com/files/files/69104919774.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383da7b37c6---99784559734.pdfIn PDF document text
    • http://hhsmelt.com/upload/files/rukalenapivozovize.pdfIn PDF document text
    • http://gearonlaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/purasisutijijanenapus.pdfIn PDF document text
    • https://brakos.it/file/87055755170.pdfIn PDF document text
    • http://breakevenpoint.pl/uploads/editor/file/moperat.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161369c6d3c37e---81200433313.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/wivatamibufam.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/96086922300.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/rituzafu.pdfIn PDF document text
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/85274153273.pdfIn PDF document text
    • http://zonwering-belgie.com/ckfinder/userfiles/files/25053657376.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/23076042293.pdfIn PDF document text
    • http://dalhousieretreat.com/cote_dor_import/admin/ckfinder/userfiles/files/60369725984.pdfIn PDF document text
    • https://shreenathtechnologies.com/userfiles/file/94455971265.pdfIn PDF document text
    • https://euchebnici.com/img/file/6604066942.pdfIn PDF document text
    • http://cl-pub.com/files/files/96564478358.pdfIn PDF document text
    • http://househouse.it/userfiles/files/36218628231.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/c26728345031fbee433ee6138796456c/35863748877.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/ed2398522d36615f0ffda2961d7a2a7d/32071130227.pdfIn PDF document text
    • http://utuin.net/files/fckeditor/file/46646050699.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/7j6ank735r95897qkr4l2ud2re/65702703893.pdfIn PDF document text
    • http://ceramkgres.ru/userfiles/file/8868271566.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/31901612312.pdfIn PDF document text
    • http://studiocalderini.it/userfiles/files/25153212265.pdfIn 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_off0000d96f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96F 10644 bytes
SHA-256: f3d870b76ca65cfb39ec54029dcd07962e95a4f0771e24959d83e3367a55a97d
font_01_sfnt_off0000f1ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CE 18012 bytes
SHA-256: 723c70ee26c7426360b98891e26bbc9baefda4e7c176431ba25d96e6003f57b8
font_02_sfnt_off000120a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1