Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb931cbb8049d5d1…

MALICIOUS

PDF

87.9 KB Created: 2021-09-18 07:25:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e060d3da4c22d9d9f2455e3a7eb7f4bc SHA-1: 08ff09c76ce41726754dee0aa196df525b7769d5 SHA-256: bb931cbb8049d5d1968320feac93e3e77dd4d2ffd8f7783de7a3c104a4173de4
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded URLs, many of which point to domains that appear to be compromised or disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to direct users to external sites. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • 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://apex-architect.ru/images/file/38644057213.pdf In PDF document text
    • http://rentator.com/uploades/fckeditorfile/pizuta.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/84248033800.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/cb86124ad15f09f4f0f4a2ebcb089489/68499379608.pdfIn PDF document text
    • https://pmrmhss.com/userfiles/file/40974997242.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/9d717e15a370f07a1c2e130c4ca95d0b/nugodifaputebipadajavi.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/vukesuba.pdfIn PDF document text
    • http://villapellegrino.it/userfiles/files/96245205204.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6a7b08c42---9418269752.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/pijajaj.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/13652099474.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/biluzot.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210904115045.pdfIn PDF document text
    • https://apexsafetyproducts.com/ckfinder/userfiles/files/43185962068.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/tijegokizejifugovugam.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/43653588973.pdfIn PDF document text
    • http://romento.com/uploaded_files/userfiles/files/13822067947.pdfIn PDF document text
    • http://e-hematologica.com/users/file/74029734718.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/0e90c54b8ace9a31986e48cf22881693/javowuvesepagak.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/92749448285.pdfIn PDF document text
    • http://cisseo.net/userfiles/files/87736125699.pdfIn PDF document text
    • https://redengewinnt.com/userfiles/file/7814922944.pdfIn PDF document text
    • http://chuanghuilaw.com/filespath/files/20210914075902.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16137195252362---xodowamebiwaxaj.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/161363d759efee---97021940858.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/64797056561.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=dragon+ball+kai+dubPDF 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_off0000f54d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF54D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010d64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D64 10360 bytes
SHA-256: dbaa1cf036b148ff4cef87a7c62f4e4a41041b4310fe7e262bee6ec24c47fa74
font_02_sfnt_off00012486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12486 17228 bytes
SHA-256: cea57e8259cf1c1076cd9aa03be7d0552401946c60a2935cdd4b5077282eaa81