Malicious PDF — malware analysis report

Static analysis result for SHA-256 8add83b8bbd1d692…

MALICIOUS

PDF

85.9 KB Created: 2021-09-20 08:55:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 5e01d9cef3e587d8865d38fd2d5831f9 SHA-1: 0d5261d85c81b81a1a74df24f8272af9afb8026d SHA-256: 8add83b8bbd1d69255cba5cdfe678216ef7f50a243f05f1d673c2aff7e0360d0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm directing users to numerous external PDF files. The presence of embedded URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the nature of the embedded links and the overall structure point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://zulassungsservice4you.de/bilder/file/nibijaguviwig.pdf In PDF document text
    • http://nissanotogovap.net/uploads/images/files/bipopejigiwofef.pdfIn PDF document text
    • https://hagabb.ro/ckfinder/userfiles/files/sidakugegiwelekuber.pdfIn PDF document text
    • http://lollanaclinic.com/image/upload/File/17219694610.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/65538690973.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/41364172398.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/sakuwikonejurevan.pdfIn PDF document text
    • http://bortran.com/upload/image/file/20210916063548.pdfIn PDF document text
    • https://ntct.dz/ckfinder/userfiles/files/xeburakifabenevumef.pdfIn PDF document text
    • http://unixsensor.com/uploads/files/202109051223009029.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/69699604418.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/38908602516.pdfIn PDF document text
    • https://kozhikodedeaf.org/admin/my_files/file/xozugekiwosekurogemewolup.pdfIn PDF document text
    • https://cubic.is/userfiles/file/73266819063.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/vivijezujaluwunugobixofo.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4c1fdcead---69606220106.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/19205907836.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/84530348782.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16136189d073c7---vemodagukax.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/60913667418.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210917115206.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/163146426537078fc8a4e037daabe4.pdfIn PDF document text
    • http://rfaaa.com/UploadFile/file/20210916025545833.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/22861993943.pdfIn PDF document text
    • http://wawa757.com/uploads/files/42521470250.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/68621790101.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=app+duplicator+androidPDF 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_off0000eb2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2A 18056 bytes
SHA-256: f7aeef2124ceb623368f19f0a731dbf77ebc8dc3f78f50140f997b115f6d3b29
font_01_sfnt_off00011a0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A0E 10288 bytes
SHA-256: 98f2b6dd2a757cbcf3845e6463e29ab9ed0e2ecc987e4ede9e1cc2dc48f2ece1
font_02_sfnt_off0001314e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1314E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1