Malicious PDF — malware analysis report

Static analysis result for SHA-256 73c201959af9e260…

MALICIOUS

PDF

105.3 KB Created: 2021-10-05 09:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ad3c7f5778a20e91397fe1afe9c76549 SHA-1: 0dca333e3801afcf884b02d9ab758ac4460521ea SHA-256: 73c201959af9e2604390bc2f65f3cc2b389c0453f0621a507c02c4e8515ed35a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to potentially malicious PDF files hosted on various domains. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm on disposable hosting, suggesting an attempt to obscure the true malicious destination. While no scripts were directly extracted, the nature of the embedded URLs and the heuristics suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://frutapac.es/ckfinder/userfiles/files/71215139669.pdf In PDF document text
    • http://rebeccaosborne.com/uploads/bugekirumimu.pdfIn PDF document text
    • http://szyldkj.com/luodan/images/userfiles/file/bagisifat.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/40778145765.pdfIn PDF document text
    • http://myxroad.net/upload/userfiles/file///18809716997.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/wotelisabinemifezodup.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/dc15795c4cecbe62f84b646b7ccd0d4f/4333118068.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/8087376713.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/zatolubaxupoxukuxugadu.pdfIn PDF document text
    • https://by-express.com/upfiles/editor/files/14894775636.pdfIn PDF document text
    • http://rotarylaspalmas.org/documentos/file/wominafova.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/67333131777.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/6c9d19c4f8b4c2bcc487b034311f930e/fixezufovobepe.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/dunixarezokofow.pdfIn PDF document text
    • http://tradotel-riviera.com/file/natuwagilafanikozasi.pdfIn PDF document text
    • https://ceylinpin.com/calisma2/files/uploads/1819208092.pdfIn PDF document text
    • http://graczeonline.pl/userfiles/file/28576474241.pdfIn PDF document text
    • http://bochkari24.ru/pic/file/97217155971.pdfIn PDF document text
    • http://lukasikgroup.pl/Image/files/ranowalugesazemevimiluz.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/xenikilagabujupilagogi.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/19739708773.pdfIn PDF document text
    • http://codienlanhminhquang.com/upload/files/29738505919.pdfIn PDF document text
    • https://xyoaa.org/sites/default/files/files/vajimijadaxebugogojunitu.pdfIn PDF document text
    • http://scantech3d.com/files/53821791906.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=mary+kathryn+muensterPDF 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_off00013211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13211 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014a28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A28 10416 bytes
SHA-256: 99f6930cd87726ed0950f61b14e5eef546bb5f71d3fc94ea55e8ad255f4c20a4
font_02_sfnt_off0001619d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1619D 20716 bytes
SHA-256: f44369a18efd2db5af6b1a35c23a82ea2e3fc514fd5d8e90a9022ae22e201657