Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bb8b8ebff1032db…

MALICIOUS

PDF

67.7 KB Created: 2021-09-16 08:28:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 2d3e805c5518af1fb52097f681c13d57 SHA-1: 90bcf07b136cae3c56733a6f3bd04c8de4fb39f8 SHA-256: 5bb8b8ebff1032db8d11677f1dc1e3bc23135b43606f135cd878c53e6571af1b
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://autopsrus.aerovents.com/ckfinder/userfiles/files/jivatalalakud.pdf In PDF document text
    • http://mayjack.com/upload/files/93172371431.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/dixasodejivew.pdfIn PDF document text
    • https://suacuasathcm.com/uploads/files/96537430330.pdfIn PDF document text
    • https://bikeid.net/ckfinder/userfiles/files/tutag.pdfIn PDF document text
    • https://laps.pl/userfiles/file/zapajafapuwunuxuzadamaxi.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a140fae592---24095858532.pdfIn PDF document text
    • https://ispartaorganizasyon.com/ckfinder/upload/files/98332601353.pdfIn PDF document text
    • http://studiomontironi.eu/userfiles/files/92284189128.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/76461397629.pdfIn PDF document text
    • https://comillaspostgrado.es/userfiles/file/visivuret.pdfIn PDF document text
    • http://teplospectr.ru/images/files/fivurijujuxagupadogufo.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/69104762444.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe58fe12c0---dedogujitedatofowinenu.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/rowojofepakaxona.pdfIn PDF document text
    • http://pyramidplaster.com/file_media/file_image/file/42310175394.pdfIn PDF document text
    • http://dogomanhnghia.com/uploads/files/dafekapuzoku.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/romedexojidapobiriloxo.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/75087100224.pdfIn PDF document text
    • https://b2bircruise.travflex.com/bot/ckfinder/uf/files/faxuv.pdfIn PDF document text
    • http://argyleliquidations.com/userfiles/files/juxoloniwamudekimawe.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xofikotuf.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/hvrpq8gj6r4odrh1garoti42fm/jafezevibuxusosirotijezi.pdfIn PDF document text
    • http://net-marketing.hu/images/files/77106049298.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=san+andreas+codesPDF 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_off0000af04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c71b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC71B 10200 bytes
SHA-256: db2b21966b15176749c69b6ebb9bf7bcc419d0165ec30961e87c1a7f33e48332
font_02_sfnt_off0000de0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0A 14344 bytes
SHA-256: f062d0e3cec2b4806d42388e7d17ceadf298f52cd42115df3f40e62d5bbfdc7c