Malicious PDF — malware analysis report

Static analysis result for SHA-256 836d1f983bbd5826…

MALICIOUS

PDF

74.5 KB Created: 2021-09-14 01:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b7fbc0a4c9a510ddf0949c02b92bef9f SHA-1: 452589ccb1c0978797b3492a30940d5c666b08b7 SHA-256: 836d1f983bbd5826c43ce0be085f2bc3882679bc6fdc0fc6cbb11a3377277f55
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. While no scripts were extracted, the nature of the links suggests a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://ekonopuntos.com/campannas/file/52694074487.pdf In PDF document text
    • http://isagenixmakessense.com/ckfinder/userfiles/files/forasisawelopenutup.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/btvvv8iu2qiukpa6l39lj9gp66/lazapawovuruzafama.pdfIn PDF document text
    • https://metricgroup.it/uploads/file/92809161476.pdfIn PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/xesamixibijevup.pdfIn PDF document text
    • http://dmkert.hu/files/file/dememukevitexad.pdfIn PDF document text
    • https://gallerylingard.com/uploads/file/31685638923.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/biragivil.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/mimegazurekanedizalawa.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/92084074993.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/79047094120.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/7516ff823bb5c951d2452c426e054b2c/70843324503.pdfIn PDF document text
    • http://kotolantopeni.cz/file/58398134349.pdfIn PDF document text
    • http://atek-ent.com/upload/file/11390241182.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/2845bd2cf2be477589599211ed5ce94a/87309258178.pdfIn PDF document text
    • https://galaxytraining.examinationonline.com/files/79878584260.pdfIn PDF document text
    • http://meijialx.com/ckfinder/userfiles/files/piroxubur.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/56843492067.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f71d482a7c---52854693729.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/vixotivaf.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ef89702bb---96084008175.pdfIn PDF document text
    • https://mlspoland.co/files/file/finax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=good+meme+quotesPDF 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_off0000c259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC259 16904 bytes
SHA-256: 1d83d435d7b1fddd99cd1875554b207f525cfc4ddab91a8d8b2114d38e5d371c
font_01_sfnt_off0000edca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105E1 10188 bytes
SHA-256: 7f4c4ebf876ecb1af7f5ee26081d5625ba8f6e5133d041f1021581376dcc7e1b