Malicious PDF — malware analysis report

Static analysis result for SHA-256 96866a88d88554ec…

MALICIOUS

PDF

97.4 KB Created: 2021-09-20 14:33:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a352ff9adf8c802cbe47af700a472ef6 SHA-1: d4783d72fad092f0b811040fe0d8fb198e5e598f SHA-256: 96866a88d88554ecbe2576e7c3f4c3598edc915e564836c8694e8b62a74bc7c6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics as containing a link farm and was identified as malicious by a machine learning classifier and ClamAV. The presence of numerous external URIs, including links to compromised CMS upload storage and disposable hosting, strongly suggests an attempt to redirect users to potentially harmful content. No scripts were extracted, but the structure and heuristic firings indicate a malicious PDF designed for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://next-engineering.com/userfiles/files/xibesumibatebuvuzerowad.pdf In PDF document text
    • http://reklama-kemerovo.ru/files/files/88711152065.pdfIn PDF document text
    • https://nyig.com/files/file/35154249864.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/likaso.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336e2e28ad7---judojivi.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/19981213778.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/rozezaj.pdfIn PDF document text
    • http://dymenahealthcare.com/upload/fckeditor/file/wunujawuxefavub.pdfIn PDF document text
    • http://birizgardenhotel.com/userfiles/file/kefusam.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614427177f79e---situtojon.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/ff3c70e4ccafbd9b12cb7c7488dc5c33/nolevipawiviwamedutaguta.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/77074165345.pdfIn PDF document text
    • https://trexanh.net/upload/files/2665414322.pdfIn PDF document text
    • http://irinabailey.com/upload/files/nifapimufodusa.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210911_034307.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/4fbbe8574dd7a2aff50f0cdf1fe89a59/jemokilon.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/3457402738.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/sosamaman.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/op8b8u9dmsab029lmvsef7lfce/nivexuzur.pdfIn PDF document text
    • http://nieruchomosciklodzko.pl/files/file/81460033700.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/dafupuvoduzufefulirol.pdfIn PDF document text
    • https://bacsionline.net/userfiles/file/23362816761.pdfIn PDF document text
    • http://ros-audit.com/i/up/file/69875567464.pdfIn PDF document text
    • http://iviltra.lt/images/files/90588773589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=fortnite+season+5+chapter+2+battle+pass+skinsPDF 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_off0001184e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1184E 17860 bytes
SHA-256: ddca1650a9c219c4b0bfda43a588d37566c213d9fa24bab990a86c9f5c986424
font_01_sfnt_off0001463d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1463D 10932 bytes
SHA-256: 9232188eb81ec20574868b0d5aafcf2390cd1497a33000095de1389b42c3daf7
font_02_sfnt_off00015f5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F5E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1