Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c342f88fe1ac741…

MALICIOUS

PDF

81.0 KB Created: 2021-09-08 22:04:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b3d38c046aa516ade5c0c2dc7da453e4 SHA-1: 51a4e6f739d5f1891ca88075922d7f8f98d0c5f9 SHA-256: 8c342f88fe1ac74158c163ef186d9f292730a5a9a9c4e9f99996673e7621d47e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as a link farm and a potential phishing or malware distribution vector. The presence of numerous external URIs, including those hosted on compromised CMS uploads and disposable domains, strongly suggests malicious intent. Although no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it is designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://krisoc.ru/uplcv?utm_term=gloomhaven+3+player+party PDF link annotation
    • http://hepiran.com/cache/fck_files/file/bofuxuwulimuxafix.pdfIn PDF document text
    • https://12waktu.com/contents/files/rusuvegawizilazixozeparej.pdfIn PDF document text
    • http://hb1004.com/userData/board/file/fetafatefum.pdfIn PDF document text
    • http://datatalk.ilvzhou.com/upload/files/2021/09/202109032223088201.pdfIn PDF document text
    • http://ping-property.com/user_img/files/vigaribowofi.pdfIn PDF document text
    • http://bxbrdh.marketsearching.com/upload/files/8784915718.pdfIn PDF document text
    • https://servauto.fr/img/user/file/nemidutekatofom.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/4986971024.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/92474679178.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/lutapexobo.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613396c85e8d8---56975544436.pdfIn PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/poruduwupedubipadexileme.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/acc51c87652503c8a0d7ca1b0be10ce2/20194776446.pdfIn PDF document text
    • https://pearproperties.in/userfiles/file/86347331933.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/jikuse.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/ea3ad7b6419df5eed6af61a2b706e2bd/8982929080.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/mirojosimopamovizafuxe.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e4b827b92---vepunilamowepufugalud.pdfIn PDF document text
    • http://crisismobile.com/ckfinder/userfiles/files/samanofobujefugutor.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/34285668468.pdfIn PDF document text
    • http://flagrant-desir.com/userfiles/file/72766617684.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_off0000dcad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C4 10648 bytes
SHA-256: fb1b593dcddf08f0286b663f3dcccb01aeb6208bd3e1ff1116256f017b396980
font_02_sfnt_off00010d0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D0E 16212 bytes
SHA-256: 17e3670b429598f87e58d666b791d7a6b507f3e634ae6ba21a752bd4c716a4af