Malicious PDF — malware analysis report

Static analysis result for SHA-256 85008cc735bf6b07…

MALICIOUS

PDF

86.1 KB Created: 2021-08-10 11:46:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a53853672cc67e980179fc31f39066cb SHA-1: 1beb1553ad141488a160c977c6de94a18f8d643f SHA-256: 85008cc735bf6b07031abd07765a6e0b36ef01d6e9ca7c381520626b0352f8a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://irlanc.ru/uplcv?utm_term=8+times+table+worksheet+pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16075dacf8313f---nofixopa.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606feb3d157dc---52248622315.pdf
    • https://hijaulumut.com/contents//files/79743963187.pdf
    • https://gemwares.com/userfiles/file/6812668735.pdf
    • https://hagakure.by/upload/editor/files/nimimiduwileguwox.pdf
    • http://controlsystemco.com/cache/fck_files/file/befesuxanekalunezetevili.pdf
    • http://arunimaflavours.com/userfiles/file/77666068908.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160abf51f59a4d---jidune.pdf
    • http://kpdb.org/userfiles/files/38504981691.pdf
    • https://capecoralliving.com/media/file/75474228696.pdf
    • http://szpital-sulecin.pl/images/fckfiles/file/1958243812.pdf
    • https://rsun.pro/admin/ckfinder/userfiles/files/karepo.pdf
    • https://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e64ea7e317---zuwumuwopopes.pdf
    • https://tyeetomsfishing.com/userfiles/file/70535027860.pdf
    • http://normandyclassof79stl.com/clients/e/e1/e16d7b8530e96d8d426d6b963c92b0b5/File/valaluber.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/5pr7puiqc43h87ls933vvipc3t/88941126940.pdf
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/45050787555.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/81275433520.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/e9ca9ad643d4c2f3817e6b76469e0378/begivusenujosoforifenul.pdf
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/ba22bb05fed846423ddd47cb2587367b/67701024080.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094576002f98---99447310877.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed2a.bin
dca1fc3d297d897b4b7403d3aab6616c6a56c1d730b245cfb7beb5183628d640
pdf-font-stream PDF embedded font (sfnt) at offset 0xED2A 11088 bytes
font_01_sfnt_off000106dc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x106DC 16792 bytes
font_02_sfnt_off00011eee.bin
86e2b0485ac073f846e3d8386768ea8b1fcc9abc91346ec61d6bee9b7e37c3d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEE 16772 bytes