Malicious PDF — malware analysis report

Static analysis result for SHA-256 92131a94ca67045b…

MALICIOUS

PDF

86.8 KB Created: 2021-09-10 09:09:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8acbdc2111b3fd2e61b607cf32ab8981 SHA-1: c5df87c0ec077f6ec06d354c72aa09235a8f1443 SHA-256: 92131a94ca67045b1820d282d7b64eca1549ad89120019741face1cbda03a41d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://rld-carbon.com/file/37186301248.pdf In PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/c94df1b773c4ecd03b69bcf5ff7aba38/migivamesuferad.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/55745830200.pdfIn PDF document text
    • https://idealist.ro/userfiles/file/vogozapowe.pdfIn PDF document text
    • http://infas.cz/images/wiswig/file/sivelusuvobu.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612f729eb9d92---folel.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613216991c0df---wixivowukukozobadexasizu.pdfIn PDF document text
    • http://clubesquilacoma.com/uploads/files/nusabowigikate.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/953c9bbe7aa8f43de4f4cb6ac39e0938/bawejipavisemum.pdfIn PDF document text
    • http://nerezove-kuchyne.cz/UserFiles/File/72956082177.pdfIn PDF document text
    • http://dkstores.gr/userfiles/file/relixeja.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/96268336052.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/fozogoderoxan.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/87a76e6fc9f909325409156f5c4d4db2/44183262234.pdfIn PDF document text
    • https://dichvuketoanvn.org/uploads/files/92703276492.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/6616185762.pdfIn PDF document text
    • http://moda-minulosti.cz/docs/momin/file/sijiboduzonuj.pdfIn PDF document text
    • http://abarappresentanze.it/userfiles/files/dozibokezunidosovot.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131519caa192---17869873404.pdfIn PDF document text
    • http://tiramisu-o.com/yamituki-n/uploads/files/90034441656.pdfIn PDF document text
    • https://areicon.com/images/file/91539038446.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210908184611.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/11052220212.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/guvolifijetesexedagijid.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/wilesex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=where+is+sd+card+in+android+phonePDF 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_off0000ef93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF93 17620 bytes
SHA-256: 20d9fcfe2692276df59f2483d2023ae46d2b3699fc5ca67e5120d1713e20ee78
font_01_sfnt_off00011da8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DA8 10460 bytes
SHA-256: aa2a4b4715027f5ea9965ebfa8d01f58e659a9ab35b36efea13415121d666b3e
font_02_sfnt_off00013558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13558 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1