Malicious PDF — malware analysis report

Static analysis result for SHA-256 f121f6eb8fa13f8a…

MALICIOUS

PDF

75.7 KB Created: 2021-09-26 19:30:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 33410cd92c1a87c402b9b69d624b9ac6 SHA-1: a2670e060c7b34d4e05e0ef2f8ad6d513efc602b SHA-256: f121f6eb8fa13f8a719d9dd00ce3f7baa7c6f102aa8d85a04a65f20020da8466
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple external URIs were extracted, suggesting the document's primary purpose is to redirect users to potentially harmful websites. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://oniceh.ru/uplcv?utm_term=7+letter+words+with+2+v%27s PDF link annotation
    • http://birdwatching.sk/media/file/57695127668.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/fuzuniv.pdfIn PDF document text
    • http://sreema.org/FCKeditor/file/xijivifufimaporosa.pdfIn PDF document text
    • http://americasbestmanassas.com/uploads/files/mekawukawujixujap.pdfIn PDF document text
    • https://qatarsecurityservices.com/public_html/userfiles/file/8425433386.pdfIn PDF document text
    • http://laduses.nl/image/file/mubofajaka.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-26/20210926120604873175.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/70632575217.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/vokolodopevoxusozemofox.pdfIn PDF document text
    • http://donleroy.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/15978938420.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/76613881410.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/lowekibub.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/22047783646.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/71825601673.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/93bf14612ce2450b9ad6b9d66e527442/98186949378.pdfIn PDF document text
    • http://mkpstroitel.ru/upload/files/tuwejobuseg.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/13339814560.pdfIn PDF document text
    • http://inoxbienhoa.com/upload/files/75725882434.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/3002375566.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/wabisus.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16136b3b36c13c---34986964981.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/63363195485.pdfIn PDF document text
    • http://karinameal.ru/imgdish/files/zowevu.pdfIn PDF document text
    • http://www.tamtrebinhminh.com/public/files/jezatekaloxoluxefagubu.pdfIn PDF document text
    • https://sieseam.org/userfiles/files/wowefafudoje.pdfIn PDF document text
    • http://makairways.in/home/makairways2017/public_html/dowalumniusa/ckfinder/userfiles/files/44990125680.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_off0000c14f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC14F 18356 bytes
SHA-256: ddcb71323ab7af328082998565ee8f94820d9e255b38e262d1fc37104fab7a39
font_01_sfnt_off0000f0e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E7 10340 bytes
SHA-256: 0ab08ca87f7b178ffb1e5407de3d36c2c46a6d54498d6aef449c64809b0cb182
font_02_sfnt_off0001088b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1