Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6bb330f1b9efe66…

MALICIOUS

PDF

75.3 KB Created: 2021-09-06 23:14:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6d8b6c12f41e00e6a2adb3e401c317ac SHA-1: dda6d58f8c4691c8e86081076e1b2558fb9c0466 SHA-256: b6bb330f1b9efe66d8302b97ebc55ee11eeb719736297ee9ba832aee6e46f5b3
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier also flagged the PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 https://pima-alarms.rs/slicice/file/sapez.pdf In PDF document text
    • http://nexxosrealty.com/userfiles/files/63207271699.pdfIn PDF document text
    • https://espiber.cl/images/uploadedimages/file/89576545646.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160acf1dbbeaba---mositu.pdfIn PDF document text
    • http://vinmexindia.com/uploads/19401065801.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611bfe9e96263---zewozi.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/c32c0708c9e131214df6be229cf588ba/vupiwi.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/291447013813.pdfIn PDF document text
    • http://erictex.com/ufiles/files/mabelotolekumunidevesuto.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3d86fa9919---lodisavin.pdfIn PDF document text
    • http://aquatherm-graz.at/files/83117512899.pdfIn PDF document text
    • http://mcutech.net/upload/2021/08/file/16300658081448583024.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b5df9fdc0---marelonusopeziwinesevuz.pdfIn PDF document text
    • http://silesiacapital.eu/data/file/latevovozuvove.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a57b1da164d---51183582784.pdfIn PDF document text
    • https://plasy.com/uploads/file/jerika.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202105/file/1621005211.pdfIn PDF document text
    • https://fotoprint.lv/downloads/file/11139736202.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b5f7a3a30---dejemofujosigivaxi.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/93708042422.pdfIn PDF document text
    • http://acril.ru/ufiles/files/janijikuxizuxage.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=doubling+rule+worksheetsPDF 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_off0000c1a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1A1 10644 bytes
SHA-256: a7add068097330950fd090c8ada88252f530de1348f26c0aa43ce18aff6b0231
font_01_sfnt_off0000d9f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F8 17888 bytes
SHA-256: fb3aa044cb921452c4c8594fb0fa03cafb61955bec867c7e053d4343edcb9cb2
font_02_sfnt_off00010763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10763 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1