Malicious PDF — malware analysis report

Static analysis result for SHA-256 83958ef5e8f6f9f5…

MALICIOUS

PDF

79.9 KB Created: 2021-09-12 23:20:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d6fe5b5d72499b6e2e8b0d812a31927b SHA-1: 83ebc8b1ef39d9f4c8504fc348de30e8e0efdf1e SHA-256: 83958ef5e8f6f9f53ae5e6ff1599f952fb1eb50fb9a3b3c7d24f0ec5a80c4c11
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://md-servicios.com/userfiles/file/18290218350.pdf In PDF document text
    • http://szolnokepul.hu/userfiles/file/94969859760.pdfIn PDF document text
    • http://nuestratierrapremios.com/campannas/file/60409771455.pdfIn PDF document text
    • http://jujucuisine.com/userfiles/file/90523144576.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/fukefo.pdfIn PDF document text
    • http://hangnhatbanonline.com/upload/files/48837673599.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///gotawazosamiwabiw.pdfIn PDF document text
    • http://azinsaghf.com/cache/fck_files/file/99205870694.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f437c25f98---84055613055.pdfIn PDF document text
    • http://pjzhengwang.com/upload/file/20210909_164728_166.pdfIn PDF document text
    • http://temple.mo/userfiles/file/44764793055.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/88380169211.pdfIn PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/9654084415.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/duligiz.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9f494637e---bejorarisamibibut.pdfIn PDF document text
    • http://qbcar.ru/ckfinder/userfiles/files/12422562085.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa/files/78185165347.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210908/files/20210908081714.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363154a9462---57859779452.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/77l99fkocju572io2kt40oh84u/36226540905.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/suxipo.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/34765206945.pdfIn PDF document text
    • http://novena99.com/uploads/files/202109021957232198.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=zelda+app+androidPDF 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_off0000d7be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BE 17068 bytes
SHA-256: 7feafeeb19f2ab285ff0f446e0a0ae8dca2f593b40f7697af483ba2148706ef8
font_01_sfnt_off000103b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B3 10084 bytes
SHA-256: b97d6c8af984194210e2e7e7d2da44c59746419cb97826c1f3c78009d1848443
font_02_sfnt_off00011a29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1