Malicious PDF — malware analysis report

Static analysis result for SHA-256 73616cfd8663d477…

MALICIOUS

PDF

78.2 KB Created: 2021-09-13 13:53:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3e7c0cc8ed657951b0a9c8c09f5c9353 SHA-1: 820537628ab5107ef936efd23b16bb42b8389556 SHA-256: 73616cfd8663d477ae0604e556c62e85ce7c93e37f73a4c41887c3ccb26ec203
146 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. The document contains a large number of embedded URLs, many pointing to suspicious domains, suggesting a link farm or phishing lure. The presence of 'utm_term_redirector=True' and the sheer volume of distinct hosts indicate an attempt to obfuscate the final destination and potentially distribute malware or lead to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://omatsuri.kr/data/userfiles/files/70647766857.pdf In PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/tuzemukefilazate.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109131215592751.pdfIn PDF document text
    • https://299-45.com/CKEdit/upload/files/rufutosidepetapu.pdfIn PDF document text
    • http://tpt.taipei/asset/uploads/files/26764403660.pdfIn PDF document text
    • http://pi-consulting.ch/download/9013343127.pdfIn PDF document text
    • https://tckontrola.hr/files/mujirefef.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/92742873516.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/93991017189.pdfIn PDF document text
    • http://studiocalcinoni.com/userfiles/files/77034192945.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b519140dda---jotawoza.pdfIn PDF document text
    • https://monographie.com/ckfinder/userfiles/files/87611432339.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161317fe69bc3e---79613627488.pdfIn PDF document text
    • http://balcimimarlik.com/resimler/files/nedopoxujikazededi.pdfIn PDF document text
    • http://sor1310.com/userfiles/file/nifalepedamozifak.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/jepisafekegomakobuv.pdfIn PDF document text
    • http://aviatechinform.ru/sadm_files/78135420374.pdfIn PDF document text
    • http://seamacros.com/upload/file/jilasapadopovalolovexizi.pdfIn PDF document text
    • https://dichvuketoanvn.org/uploads/files/woribepijo.pdfIn PDF document text
    • https://studioconcept-stand.com/fck_userfiles/file/87793277475.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/28314648473.pdfIn PDF document text
    • http://fthyhs.com/resource/docContentImg/file/2021-09-11/e9fa72d85496263cd5fad43711216976.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/vagegewije.pdfIn PDF document text
    • http://globalsocialwlefaresummit.com/app/webroot/uploads/ckuploads/files/lotuderuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=android+12+imagePDF 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_off0000d060.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD060 16980 bytes
SHA-256: 794f3cb6df51053a3acbb8ed420f3f492f5a541e9d3b529d62c76fed1502b9c5
font_01_sfnt_off0000fc33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC33 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001144a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1144A 10432 bytes
SHA-256: 3d3130f8bc399f5e6b067b00ed89295df8576c4f28823f29aed2994f8d4ca483