Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8d3aeb439420a1f…

MALICIOUS

PDF

90.4 KB Created: 2021-07-17 07:18:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 25cde76c4f8708b1a4463e22b36634ba SHA-1: 42c895c4c4e6090ba3ab27c17e7b02b13dda6f19 SHA-256: b8d3aeb439420a1f28898aebdab9f1cdb7bf1ffe0a17a62bb1db793b2da56612
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple embedded URLs pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated and contains no readable text, suggesting its primary purpose is to host or redirect to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/f6dff60615de60d90d89ba92fbf8e0f3/9841588640.pdf In PDF document text
    • http://musorcentrum.hu/files/article/file/batotonomo.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/xalezuzufusufikinis.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160af9ddfcdacf---87697143645.pdfIn PDF document text
    • http://soft-pro.hr/upload/datoteke/xafezezuroxiwabil.pdfIn PDF document text
    • http://yuha.be/_files/file/zisolapiratatumav.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/xuwujujolaniwoxowile.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/34643658239.pdfIn PDF document text
    • http://cjatkinson.com/userimages/77462142072.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210714153145107.pdfIn PDF document text
    • http://teplospectr.ru/images/files/dutisexafatebesid.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/16101267143.pdfIn PDF document text
    • https://airflow-skateboards.com/upload/file/692654927.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/a4ba9d8b9ec6a98739d546cd63d3a6be/notenusodomuzesikitu.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/94f4a7a52e90e24a7c1512a6d9510184/38705476893.pdfIn PDF document text
    • http://bjeclinic.com/ckfinder/userfiles/files/xedaxot.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b21d62bed41---57126423244.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/ff84e6935f77318b322722c0bec82f8b/bidufires.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/6456135229.pdfIn PDF document text
    • http://kezmosas.hu/files/file/95979755349.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/tigugevutasagixu.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/keuoqob924l3n8eb7jn5g3o681/tusamuge.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7825e0fc92---84162816050.pdfIn PDF document text
    • http://brooklinehs1964.com/clients/6/6a/6a3559cec3eb17f551da2d864c8c85ab/File/pamadijunisatugi.pdfIn PDF document text
    • http://bkbflooringusa.com/userfile/abbey/file/31378467878.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=new+blood+pressure+guidelinesPDF link annotation
    • 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_off0000ff7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7C 17084 bytes
SHA-256: eb2c26eca987b050221c750c8e7cae2c21633fa95cd4b05ef1e65b85cd605ede
font_01_sfnt_off00012c51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14468 10612 bytes
SHA-256: 810bc5dd3d340103327c3d9fcb44b5a3471fe515920c2ec7de95e1b5d356cd8d