Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31fc0a83879df37…

MALICIOUS

PDF

74.9 KB Created: 2021-09-12 01:24:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 76b7eeae3bc45647875b3caea3ca7619 SHA-1: 6dd655913cbe92a875afed8d53949df21bae6909 SHA-256: b31fc0a83879df37cb94171eba8105f54f7d637306c78af54f690cb17f8a7175
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://tonioloclaudio.it/userfiles/files/jemezikuwowezukekujo.pdf In PDF document text
    • http://ok-poland.com/userfiles/file/83573963656.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/35288559709.pdfIn PDF document text
    • https://walnutcreekguide.com/wysiwygfiles/file/zudeleragopapumotasa.pdfIn PDF document text
    • https://yourwebcenter.com/files/file/xilufe.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/28681555891.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/sowedobagereruvew.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/wusolutelitob.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/jijodibusuwufivinivaliro.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16136a108f3439---nelumager.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/17439828336.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbe0681572---66983614955.pdfIn PDF document text
    • http://wamer.org/userfiles/file/92811360001.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/71746969783.pdfIn PDF document text
    • https://niagarablock.com/application/webroot/userfiles/file/48783823218.pdfIn PDF document text
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/xegaxojojivinilan.pdfIn PDF document text
    • https://ovistar-dz.com/ckfinder/userfiles/files/sazopixeli.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/sevomafunij.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/gipukizajorejavuxemima.pdfIn PDF document text
    • http://zhatuogz.com/uploadfile/file/46032059502.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161379ac24ffb3---tonorabeverotogizif.pdfIn PDF document text
    • https://hediyelikhanem.com/calisma2/files/uploads/31166856351.pdfIn PDF document text
    • http://willowslakerhea.org/userimages/10049501237.pdfIn PDF document text
    • http://tpokebar.com/uploads/files/15467415549.pdfIn PDF document text
    • http://hifitness.hu/userfiles/file/36549550795.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=flv+downloader+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_off0000c202.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC202 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA14 17536 bytes
SHA-256: 99d6dc12b8869dbb18ab76b806afe4fb546f40aa0f63627111e7dc0378d11769
font_02_sfnt_off000106f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F7 10248 bytes
SHA-256: 7885edb4d3986eebb24350fb2650202e1ee4706d462e3aa46f97d8b36272b5b9