Malicious PDF — malware analysis report

Static analysis result for SHA-256 76f31caf26ae5d15…

MALICIOUS

PDF

78.7 KB Created: 2021-09-07 15:30:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 6275ce498de584466e7a5949a7167363 SHA-1: 85cc66c0424905cd51904418f212ba2a756b60e3 SHA-256: 76f31caf26ae5d158513aeeaf9be399cdf31b72bf090e23d095b788cfaa244a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is a PDF that contains numerous embedded URLs, many of which point to compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate that the PDF is designed to host a large number of links, likely to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://synerhu.ru/uplcv?utm_term=2008+pontiac+g6+gt+repair+manual PDF link annotation
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/c8ed8e10c3c296cee1afde5f1bf450ae/1460862103.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/vorasujeluwif.pdfIn PDF document text
    • http://habitat3.eu/userfiles/files/xilafewukujajoraxodun.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/wefir.pdfIn PDF document text
    • https://progin.swiss/ckfinder/userfiles/files/nokixoteninazoxoza.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/160adb4017f9b9---perujomofibubijijidaw.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1e6b57f73---tadovub.pdfIn PDF document text
    • http://fatamorgana.fr/uploads/assets/file/vivujozonevejetinuxa.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/pidig.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0ce87cb37---jufaladulomep.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/34770175280.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/dcd976d7043b9b4f341eb01d4a52b447/49671055613.pdfIn PDF document text
    • https://aromamarketing.md/img/files/fasabipineruwif.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/728b1fdc40996d2e0a412933bfe58cbd/biweberovufaferamuba.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/pizidubadujopidiberot.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/810f4p3mblrjb4nj4jk0tnn6vi/21472282383.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/gelugago.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/98206220977.pdfIn PDF document text
    • http://innotack.com/userfiles/files/9938264138.pdfIn PDF document text
    • http://zkpower.net/upload/files/83091190442.pdfIn PDF document text
    • http://phuvuongcorp.com/luutru/files/7615478250.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/pudewukudonu.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/qb2to81713o92mf24eknellrd3/vubasebilekavujabumujo.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/0576dc4d19dc8ddc747ed712431cc27a/54046957993.pdfIn PDF document text
    • http://charivne.info/images/file/kojakigaxudonexezikilefe.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d66f41dd6d3---8471314701.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_off0000cfc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFC2 16748 bytes
SHA-256: f3802c88d20629371a6e27c484bb3e4273bfa7cf7e85b68a29dd17a9e3ab3e93
font_01_sfnt_off0000fb30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB30 11168 bytes
SHA-256: 85912a8d06ed04fc56b9d75680dba4c6ef0a4c7b76ba3227e1e7860a1fbc0e8b
font_02_sfnt_off0001155c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1155C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1