Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf3b5c21d4481100…

MALICIOUS

PDF

84.9 KB Created: 2021-09-23 06:51:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cd07e17d63d37dc518ed961696776c3d SHA-1: 9bf3f3ba9e7c0eef31af4f4ea03831fe73368455 SHA-256: bf3b5c21d448110051c33f2989ae8b33fddae781eec74c80161fa9ccc4f589f7
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous external links, many pointing to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://zhengfutz.com/v15/Upload/file/2021919256483880.pdf In PDF document text
    • http://specimport.by/files/files/nuzedevojiboxus.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/64721741978.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/36422822851.pdfIn PDF document text
    • http://buyyoutubelikes.com/ci/userfiles/files/19726924881.pdfIn PDF document text
    • https://oolong-dining-co.com/webroot/editor-uploads/files/laxinugelulojipugelilodo.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/fatetabowavokoxikepi.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210916120324.pdfIn PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/jimuzititudizi.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135210656929---xidedilefa.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613f6fd196d9e---37359945785.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/55890885503.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/5949834823.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/kakizanolujaf.pdfIn PDF document text
    • http://clinicaveterinariabilancino.it/userfiles/files/36360924225.pdfIn PDF document text
    • https://perfecthospital.net/FCKeditor/file/jovoxopexirojenuk.pdfIn PDF document text
    • http://ficfart.org/userfiles/file/61829729374.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/38580536391.pdfIn PDF document text
    • https://jocafoto.com/fotos/file/sisoreserajuruvejufas.pdfIn PDF document text
    • http://alidongdong.coco1490.com/upload/file_folder/file/53592828162.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1613eff68a736c---begeridiwidikubo.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614b014390c9e---26568137887.pdfIn PDF document text
    • http://seattlebestteriyaki.com/uploads/files/gerodalununapukujalado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=android+support+library+not+in+sdk+managerPDF 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_off0000e491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE491 11164 bytes
SHA-256: 8582beb9dec21a64d631d782c0fadb68d24b939fc923d46170e1c48bb71a5e92
font_01_sfnt_off0000fe43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE43 17900 bytes
SHA-256: d5af997b4523e5fe12aaddc7b439dd987751ffb08609b64be3dfc6bf034fcd9c
font_02_sfnt_off00012d50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1