Malicious PDF — malware analysis report

Static analysis result for SHA-256 852d1a5d67674d7d…

MALICIOUS

PDF

78.1 KB Created: 2021-06-15 15:30:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 45ba6b21e7ac8e1fae11a9cfb04cbd87 SHA-1: e451ddbdfebcc502123382d6c047649a4f78b297 SHA-256: 852d1a5d67674d7d3c2ff978259ba19a1dbecf292804f77d6f2131cf1a55c40a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The document body is heavily obfuscated and contains what appears to be metadata from the wkhtmltopdf tool, but no clear textual lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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=how+to+get+baby+bowser+in+mario+kart+wii PDF link annotation
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/acdcdb7c7f81b5f15b9da083f67dca9d/vexivaxil.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rimuwegopu.pdfIn PDF document text
    • https://stayatrosetta.com/wp-content/plugins/super-forms/uploads/php/files/mi0l35fujjn8p2ev9kt582s4tb/46173535597.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/zedopalukomaga.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/fomogomewovufuwaxanoburoj.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/xosejufonalibo.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/29b68df2777bea58dc440d6b0f5ca45a/bulipunokapoduxi.pdfIn PDF document text
    • http://lateonsettay-sachs.org/userfiles/file/83510232998.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609b31622f709---83203623777.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c876f500fe2---sagufuvugasudadal.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c70feb003a0---rekolojatamijedubufuzuxo.pdfIn PDF document text
    • https://ratsimae.eemedia/contents/file/lajule.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4f10fe4433---zobezupelibonu.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//katujasufovazulu.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/masovi.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/djfbs1lvvqfnk2svp62c5m9sv2/78985562973.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/53613629851.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609445af54a95---fenezaduxuxovovovi.pdfIn PDF document text
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/fcc75e82abce515f171732b74e379e41/57456689588.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000f50f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF50F 5332 bytes
SHA-256: 36e4f3c558c3f8fb20e750822160c95f28129887a0219d1fcf3f5966fefbdd16
font_01_sfnt_off00010739.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10739 10484 bytes
SHA-256: f06e42963117b9109a43026787d4af8464398e2ea283774794e7d8f577e60778