Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4271c0cbf287426…

MALICIOUS

PDF

82.6 KB Created: 2021-09-10 21:35:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 15b03dcb9e97031b4165e082ba89d98a SHA-1: ab82db27c0a66f56b82e31a21cfb22639a3dc431 SHA-256: a4271c0cbf287426fad400e1ff9fc32a07003c884ec17abea67e453e682cc112
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high probability of malicious intent. The PDF contains numerous embedded URLs, many of which are part of a link farm strategy, suggesting an attempt to direct users to potentially harmful content or phishing sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://heritagecambodiatravel.com/userfiles/file/39655644914.pdf In PDF document text
    • http://auto-spec.ca/fck/file/4324069803.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/85591343608.pdfIn PDF document text
    • http://way-of-spirit.ru/upload/file/37073560.pdfIn PDF document text
    • https://nichecnk.leaddeehub.com/userfiles/files/56538321757.pdfIn PDF document text
    • http://manenshop.com/upload/files/69918096681.pdfIn PDF document text
    • http://fornacedelia.it/userfiles/files/21645500492.pdfIn PDF document text
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/47929539847.pdfIn PDF document text
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/21923619393.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/53310759686.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/37608803856.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/kikilojawu.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/wifidozodadasolafusig.pdfIn PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/26219627406.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/9a883d5ea95f1d8bf31e8923746a2296/79836213410.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/9dvdugijiu2se7npigtlne3mjh/vefiramiwetokivatet.pdfIn PDF document text
    • https://www.hermanosvalerorecio.com/ckfinder/userfiles/files/pitisoledixeb.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/biboditatalawokovus.pdfIn PDF document text
    • https://12tiga.com/contents/files/jotoseku.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/ponejavadipogenumemaz.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109090212023788.pdfIn PDF document text
    • http://zzfcw.com/file/fkimg/file/pizojadijunoridepefilutuz.pdfIn PDF document text
    • http://sartor.ru/upload/files/rakonesunewigepi.pdfIn PDF document text
    • http://alteredcompta.com/buddha/ckfinder/userfiles/files/71791068240.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=ez+file+explorer+pro+apkPDF 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_off0000d710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD710 20972 bytes
SHA-256: 65f31e77b8ca135e137b5796f7c4efa8074160905713b557775a3e707d771ce4
font_01_sfnt_off00010e2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12641 10220 bytes
SHA-256: d26e54d2bd5c20e9cd82e6f9cdb318596fd9d985963f95deb60c59f37fc7f31d