Malicious PDF — malware analysis report

Static analysis result for SHA-256 10838cff6b91d3a9…

MALICIOUS

PDF

85.0 KB Created: 2021-08-28 11:58:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e9ef10cf3c1ec349c30f494f0325d320 SHA-1: bbb433cf136bbf9ea8f394dc42199bcd6461398d SHA-256: 10838cff6b91d3a9c024738ab0e446e82e27e51d7cec58de5ebc74f375e77d55
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://skyzoan.com/cake/beta/userfiles/file/farobelilaloramojeda.pdf In PDF document text
    • http://purepassion.pl/userfiles/file/40257275155.pdfIn PDF document text
    • http://ventmetal.ru/userfiles/files/vitujeweviwidumana.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/84987589930.pdfIn PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/jifudiwabamagizululive.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/o11tbmf50q3aforrviq843dml4/fepufoloruximidawam.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f1be56b7288---99980029521.pdfIn PDF document text
    • https://affordans.com/ckfinder/userfiles/files/43045624647.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/lemuwirexexewowoval.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/da4cb5993fd8cd8cf8a006203504c625/vevuxitegipi.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/77186099351.pdfIn PDF document text
    • http://www.majbrno.cz/uploads/files/1489496809.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b967a99932---98760525294.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-8-17/20210817205715441620.pdfIn PDF document text
    • http://walthamclassof1985.com/clients/5/52/52060312c10aa816a718e90a19a6a7a1/File/tutumanivusufema.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/f8af65f32752f799f5c215b00cd6ef8f/nurotidox.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/70649157431.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/7909891614.pdfIn PDF document text
    • http://mpu-beratung-brendle.de/userfiles/file/84758518318.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/1324rnaupmlttm5h801dvq4483/19752985470.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/ttrefpv3pkb7hrhbmovtkd48g3/gilavemevozomowupa.pdfIn PDF document text
    • http://dienmattroigiasi.com/uploads/files/19950452668.pdfIn PDF document text
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/26597542797.pdfIn PDF document text
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/vn4c4phi7e1sllri42df74vvfa/ridada.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/titimeb.pdfIn PDF document text
    • http://boeschfamilytravels.com/clients/43210/File/kejupaxetajifimazodige.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/40010995465.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=extract+pdf+file+to+wordPDF 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_off0000e30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 19636 bytes
SHA-256: 3c810e15561862b920d8b2e6d4a5bc5b5de08102e965e81531f646ea67c8ea1e
font_01_sfnt_off000115aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115AA 10512 bytes
SHA-256: ba0970bc694dd16afd7614b38e4259bdacfe77a62ab393e0e8bc6b863fd254ce
font_02_sfnt_off00012dc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DC7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1