Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bcd602512ffa857…

MALICIOUS

PDF

69.4 KB Created: 2021-06-14 22:33:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 6d160e15ef02f4d0bf754f555c588a23 SHA-1: d31bde00fbb942d4cba6db2311139294011ac2ea SHA-256: 3bcd602512ffa857d9445d75d20bebb529e7106a0a2be9dea843cf68e895ae80
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The presence of the 'wkhtmltopdf' string in the document body and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate the document's purpose is to act as a lure. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://allytemp.ru/uplcv?utm_term=xlsx+to+pdf+convert+online PDF link annotation
    • https://htchninc.com/d/files/55598602425.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/50518472848.pdfIn PDF document text
    • https://folklorebridge.eu/uploads/pictures/files/44462041129.pdfIn PDF document text
    • https://alutat.com/data/file/xasutiga.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c07d3a52a35---41798404059.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16090ad09117e9---zizunobamikofusakok.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/415b1957dda6a9ebb4acca565a040bc6/suwisoz.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/puluteralokufapigekorog.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/905f48a1dd087553012c1b95a5592523/54397014197.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160a17b5edeb92---18972318929.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/4ntk50up3k3jjg9akbbmsqj3l5/wutoviliritakamevamiji.pdfIn PDF document text
    • http://ck-kutnahora.cz/gais/image/file/48925559822.pdfIn PDF document text
    • https://bonacorsi.it/file/pawexizej.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16091f092cbe68---27020002955.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608267de90de0---62984094529.pdfIn PDF document text
    • https://bharatbiodiesel.com/userfiles/file/86902969937.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/e4179036dc47ed5c20b9b64d0b642ed2/zukenexuvekid.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4DC 5044 bytes
SHA-256: ae784bb8ea3288315aec324675f59e2ea71076166c1682581fdeda409278994b
font_01_sfnt_off0000e621.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE621 10224 bytes
SHA-256: 3a8f6bbe0b49c5852625d553760155914d6bf701aac92b2b18c1eb1346bbecf6