Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c6d5135bdf31de…

MALICIOUS

PDF

75.1 KB Created: 2021-09-26 15:51:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 98d5a835aa44d0f4be222e7d255f2f95 SHA-1: 5153b4156d41b16d375436fb3376bcb0455687b9 SHA-256: a5c6d5135bdf31ded40f0e604c31f28bf63d3d3867970a82d3fe488b83f69a9c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it's a PDF link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution attempt. No scripts were extracted, but the PDF structure itself facilitates redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://synerhu.ru/uplcv?utm_term=safe+mode+lg+optimus PDF link annotation
    • http://superazs.ru/images/news/file/vogebaromebezukeramolov.pdfIn PDF document text
    • https://aathichudi.org/userfiles/file/56930850096.pdfIn PDF document text
    • http://goldartline.ua/userfiles/file/wamekogitemadirenasevo.pdfIn PDF document text
    • http://kangmeideyiliao.com/uploadfile/file///2021090316544471.pdfIn PDF document text
    • http://rc-modeller.se/images/file///lozodewitokurivanutajiv.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/rufav.pdfIn PDF document text
    • https://lhorizon.ca/uploadHorizon/file/texelaturuj.pdfIn PDF document text
    • https://euronuts2009.ge/files/files/43092262100.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/69190371449.pdfIn PDF document text
    • http://mawratanews.com/armedia/uploads/files/rumim.pdfIn PDF document text
    • http://totoumi.jp/upload/file/22705960385.pdfIn PDF document text
    • http://taeguektour.com/FileData/ckfinder/files/20210919_7BC57F9B93C12CB3.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/b4887a06f4aa8456dd4d7682835564cb/92642749257.pdfIn PDF document text
    • http://cluboutletmoto.net/campannas/file/39953232956.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/27120279611.pdfIn PDF document text
    • http://annabarons.com/files/files/xivibi.pdfIn PDF document text
    • http://abw10thstreetne.com/uploads/files/93190464152.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146d02f61979---65849650839.pdfIn PDF document text
    • http://studioarchperissinotto.eu/userfiles/files/wusevuweranetukipu.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/93796686039.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16147420bb96a6---texedikisuzum.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/59986312967.pdfIn 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://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_off0000bc4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC4F 10812 bytes
SHA-256: 1aada5915f098800987174deef28537a0a1bdbba3adc12dd04fd2b24b8805995
font_01_sfnt_off0000d508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD508 19108 bytes
SHA-256: afe43d69ca4fa882232ecd631d813608e516b805a9e5e8cd981a7b56e60e821b
font_02_sfnt_off00010729.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10729 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1