Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd5a451cd68c1af1…

MALICIOUS

PDF

70.5 KB Created: 2021-09-13 19:15:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c9404f528613ff280e7188a59201ddeb SHA-1: 9bde2735afb3c93e64344f64bac44d54a663bf87 SHA-256: fd5a451cd68c1af179ca82f74094fba109a40d83f38e24b3b987edd8c5f78d32
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous embedded URLs pointing to various domains, many of which are likely disposable, suggesting an attempt to obscure the ultimate destination or distribute malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://rainhouse.kr/data/editor/file/91539738661339849d4728.pdf In PDF document text
    • https://bda.ch/ckfinder/userfiles/files/geririsojuz.pdfIn PDF document text
    • https://mundolibre.cl/uploads/userfiles/files/miburokotelidaf.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/39122751984.pdfIn PDF document text
    • https://openkomm.yussfone-crm.com/userfiles/file/tutatikuzofifuluturi.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/27987806846.pdfIn PDF document text
    • http://bienbao.org/uploads/files/22126591583.pdfIn PDF document text
    • http://gespk.com/userfiles/file/juzifejuzinovi.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/mixaborakunekuzukap.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/jakurikidagipet.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/vivagabufo.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/666975792.pdfIn PDF document text
    • http://fgosvo.ru/files/files/nivatazob.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7d893e8e0---41170486991.pdfIn PDF document text
    • https://immo-macedo.lu/userfiles/files/22270308178.pdfIn PDF document text
    • http://psycare-spb.com/userfiles/file/21363758861.pdfIn PDF document text
    • http://intertravel.hu/_user/file/lidabus.pdfIn PDF document text
    • http://hstairan.com/FCKeditor/editor/filemanager/connectors/php/userfiles/file/vujanikuxudofaluz.pdfIn PDF document text
    • https://patc.fr/imagesfile/35624173164.pdfIn PDF document text
    • http://hosungtour.net/FileData/ckfinder/files/20210904_C907CCE29F13A97F.pdfIn PDF document text
    • https://ruedi-leuthold.com/userfiles/files/65577488117.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aba5fc9151---46978538668.pdfIn PDF document text
    • https://tylbm.com/Upload/ckeditor/files/2576200881.pdfIn PDF document text
    • http://nensi.si/upload/file/rekugumudefir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=runner+626+for+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_off0000b4e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E6 15564 bytes
SHA-256: 7c716233570782080d0cb44c560aa81253915d3d08ef7ddf386a1374de5c1e84
font_01_sfnt_off0000dc86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f49d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF49D 10468 bytes
SHA-256: a1072c6c9e83073d98c441822c42d47786518017ffcbfe5d6932172453c32347