Malicious PDF — malware analysis report

Static analysis result for SHA-256 8810919b24c81dbb…

MALICIOUS

PDF

90.1 KB Created: 2021-09-16 13:16:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 598d67e833f408fcaf0187c4cc6a0762 SHA-1: 28c9e31980cec121528082454ddd789e4655fcec SHA-256: 8810919b24c81dbb5ce791f2e5649e4b29409ac2df227b66011b7373b9fc3b94
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple domains, many of which are hosted on compromised CMS uploads or disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://duocvinhkim.com/userfiles/file/volonamijunisifeki.pdf In PDF document text
    • https://costarica4d.com/contents/files/45339618396.pdfIn PDF document text
    • https://valstybestarnyba.com/upckfinder/files/20362756060.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd8d9066c2---98602782928.pdfIn PDF document text
    • https://nstyapi.com/resimler/files/xolugudonizalijoranalefud.pdfIn PDF document text
    • http://dalboncostruzioni.it/userfiles/files/gebunepagejewinuvubexeris.pdfIn PDF document text
    • https://solelane.com/ckfinder/userfiles/files/ligotaxisulaniwafete.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/u7ule7eot5t7636978u8g7rh82/mezarodiridizomik.pdfIn PDF document text
    • https://10s317.com/uploads/files/202109090846267343.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/70064b5f1fef00ffd30ef8684e2c397d/nokoge.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/petelorar.pdfIn PDF document text
    • http://amghanoi.com/images/ckeditor/files/gozuzaxenapada.pdfIn PDF document text
    • https://buka.ru/sadm_files/bepede.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/wozodaloj.pdfIn PDF document text
    • https://onlinendttraining.com/files/ganezurubifesugobonimu.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161409b267d6ae---81713179276.pdfIn PDF document text
    • https://ciela13.leaddeehub.com/userfiles/files/binananokifofatusulub.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/lasosajutitovavog.pdfIn PDF document text
    • https://loctra.net/userfiles/file/38367914387.pdfIn PDF document text
    • http://unibox.lv/files/text/42526501628.pdfIn PDF document text
    • https://serrechevalier-skifun.com/imagesfile/buzevetanawevusavip.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d86d2af408---32752545149.pdfIn PDF document text
    • http://longtra.vn/userfiles/file/37056028812.pdfIn PDF document text
    • http://tochalco.com/uploads/files/53879683837.pdfIn PDF document text
    • http://cosyromania.com/media/file/21990889483.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=custom+fortnite+skin+generatorPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#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_off0000ff42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF42 18928 bytes
SHA-256: 0ef0be3a19f0b2acfa3e65795d876c50ab8038df16aeecb5f8e89b2cd18afb99
font_01_sfnt_off00013003.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13003 10736 bytes
SHA-256: dd6f66b0b368606eb9e66a51e48d230dda2e83d747555731a14ab166d536e473
font_02_sfnt_off000148c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1