Malicious PDF — malware analysis report

Static analysis result for SHA-256 c10dc155c09211e0…

MALICIOUS

PDF

88.4 KB Created: 2021-09-21 22:52:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 80c470dc12d169c5fd42349f57e3cd30 SHA-1: dd8a9fcadc1a445222699b150551f848a48b7230 SHA-256: c10dc155c09211e020ed6a3476d6e08fbc9478cf639ecaa4daa5692a2a2ca391
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to compromised websites and disposable hosting, suggesting a link farm used to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://krisoc.ru/uplcv?utm_term=redmi+note+8+pro+price+in+china+2020 PDF link annotation
    • http://aromacosmetics.bg/assets/userfiles/file/25385347089.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/71250994405.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/32096456696.pdfIn PDF document text
    • http://jacsonsfurniture.com/userfiles/file/35650633110.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364e928ca8d---jenafavizurojuji.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210905111718_1194227632.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1ad2c8981---37399592643.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/tezabomurelakumutofejedo.pdfIn PDF document text
    • http://pbhdom.eu/userfiles/file/koxeraxofuvazere.pdfIn PDF document text
    • http://fruhmann-elektrotechnik.at/xafagupunulawejet.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc0de60254---27456560707.pdfIn PDF document text
    • https://dorfadvertising.com/ckfinder/userfiles/files/jiviwuwefiwororik.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/vesuvedup.pdfIn PDF document text
    • https://777mto.com/contents/files/mijejurobosasik.pdfIn PDF document text
    • http://xn--80affcyoc0ac1f6a.xn--p1ai/admin/modules/ckeditor/ckfinder/userfiles/files/45332198701.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/44331172625.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/46997914494.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/porajeluzedivamesap.pdfIn PDF document text
    • http://01host.ru/userfiles/files/36027591029.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/1451016109.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/12649191891.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/napevudo.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109040226557662.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/gekipibe.pdfIn PDF document text
    • https://luxurybaths.marblobaths.ph/app/webroot/img/files/vefukikajexozozi.pdfIn PDF document text
    • http://medicom.pl/userfiles/file/babesuburumerarufelin.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_off0000ee43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001065a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1065A 11060 bytes
SHA-256: f519b5acc928f4aee0c1caa4ec196d864ff637a0309a126eb97f0d971b716924
font_02_sfnt_off00011fec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FEC 19800 bytes
SHA-256: 824ad2e368ffb2dbba349e52f180945d10921c5723e307bb8a2a310df9fc4c0c