Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c8b70d4a5c80fe3…

MALICIOUS

PDF

80.7 KB Created: 2021-10-14 22:50:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: f8d88942a64933def06335df8f8e45ad SHA-1: e61f8dfca1556c8dfe502cd9413805f997fdaa66 SHA-256: 0c8b70d4a5c80fe3b338f7f7515855cda630c061c2b5ce4e422739f9f2d2557a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using many distinct, low-link-count hosts, typical of phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://intertexmedical.com/userfiles/files/birazuporovipajunus.pdf In PDF document text
    • http://picart-personal.pl/fckupload/upload/file/guvovijaxugexasewar.pdfIn PDF document text
    • https://pyccenter.com/images/Upload/file/divamokexibefupijikopipo.pdfIn PDF document text
    • http://hejia-ele.net/upload/3101415080.pdfIn PDF document text
    • http://i-physiology.ru/upload/mowosukebegasik.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/zebebozekapugiv.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/xulepobelo.pdfIn PDF document text
    • https://henseltech.cz/userfiles/file/ravedolutudujiwitokudano.pdfIn PDF document text
    • https://dauglita.lt/components/com_mijoshop/opencart/image/data/files/34143604645.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/jorufubi.pdfIn PDF document text
    • http://internet-trade.eu/UserFiles/file/74612303317.pdfIn PDF document text
    • http://studiolegalezullo.eu/userfiles/files/66409494557.pdfIn PDF document text
    • http://www.pranabkumar.com/fckimages/file/94282226951.pdfIn PDF document text
    • https://lifetides.ca/cambridge/uploads/files/tosovosipujenuwijikap.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/22885375472.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/xaxirugelimabolaf.pdfIn PDF document text
    • http://bourgogne.annuaire-regional.com/ckfinder/userfiles/files/95070115507.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/nikelawepugunavosulameg.pdfIn PDF document text
    • http://evrofurnitura.by/elax-furnitura.ru/uploads/files/17779619652.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/nigewagenivexikemomi.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/4782171402.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1616373f50cd90---97083176431.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/fijibudimovogus.pdfIn PDF document text
    • http://vssteel1999.com/ckeditor/userfiles/files/88949571293.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/xPAns0MRe5M/uplcv?utm_term=diffusion+does+not+require+the+cell+to+expend+atpPDF 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_off0000d663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD663 17768 bytes
SHA-256: 14796831d59ac5d0234b76767eff2339239c178f55bf426974081d77c7774c60
font_01_sfnt_off000103a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB9 11068 bytes
SHA-256: c955c68ed56a6d4181a40e3d1a9ff64c1810409eca1db699847b0645f9986d28