Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb8aba84f1f545bf…

MALICIOUS

PDF

78.5 KB Created: 2021-10-13 05:38:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cadebd44609f21e61a6776c5a1e188b1 SHA-1: 899dc786b0e5261f076f962b58069abc51723d4a SHA-256: fb8aba84f1f545bffbbbc0fc22cbea35792f8b1b4fe773251820e675cb41689e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to other PDF files, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a multi-stage attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://wastran.ru/uplcv?utm_term=all+star+tower+defense+codes+for+mounts PDF link annotation
    • http://cn-polylysine.com/d/files/likivedixitozowisasij.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/83982885436.pdfIn PDF document text
    • http://fittbikese.hu/files/file/2898774440.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153524d429d0---demenozup.pdfIn PDF document text
    • http://vietcem.vn/public/default/ckeditor/files/70193906145.pdfIn PDF document text
    • http://100gastro.cz/soubory/files/70443623302.pdfIn PDF document text
    • https://airbays.com/userfiles/file/63858162249.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/47097148637.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615b14dfdc2d6---66671092874.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147799f55b87---95278857041.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090800001128.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1614c0db8861f5---58294256394.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/fivenulajur.pdfIn PDF document text
    • http://ptairsupply.com/userfiles/file/64518435167.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/56276013437.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/23213193466.pdfIn PDF document text
    • http://iowatriallawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ralokibazafut.pdfIn PDF document text
    • https://halead.com/uploadfile/1632379741.pdfIn PDF document text
    • http://dcbestwings.com/uploads/files/85135660543.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/fudad.pdfIn PDF document text
    • http://presupuestos.pavysan-bigmat.es/ckfinder/userfiles/files/tosasoxezeger.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/gikuxofowumotilepinida.pdfIn PDF document text
    • http://classicalgardenstatues.com/uplds/file/jiwuvonojagiri.pdfIn PDF document text
    • 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_off0000cb10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE322 18812 bytes
SHA-256: 3e16478368f4c962d9aade9299af2141b2bc5bef0f56c37a14979e086c788c98
font_02_sfnt_off000113ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CA 10712 bytes
SHA-256: 0f19ba61cf2d5fdf29c6454113338bc98f6b348885b2c84f7f3902e7087697b8