Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff110e010c940fec…

MALICIOUS

PDF

83.1 KB Created: 2021-09-08 19:44:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b9269d7d1d1787e02ccb4ce4b92d48ce SHA-1: 220859c814653ed370107ac921eb34461010cfa2 SHA-256: ff110e010c940fece135cb2c1bed839d7458f09d601ebea114101e80a2a81450
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for initial access via spearphishing attachments, likely leading to further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://harlit.com/ckfinder/userfiles/files/20210903_231300.pdf In PDF document text
    • http://zentrumok.com/userfile/files/jusuwovazekedomuwono.pdfIn PDF document text
    • http://cameragiaminh.com/upload/files/roxevigixizusafiki.pdfIn PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/37898990779.pdfIn PDF document text
    • https://terminal.hr/userfiles/file/lodemoso.pdfIn PDF document text
    • http://vangphutai.com/images/uploads/files/74307532692.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/92145318994.pdfIn PDF document text
    • https://davnosti.ru/upload/wovanafibiwitojiwuja.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/88393485764.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/8058309c3c3af438a59f866d553d9477/rajujobuzixaruti.pdfIn PDF document text
    • https://maviet.vn/upload/files/kinivujetojosajubefinetas.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/reboresituzuwiridexofu.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/97304743860.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/94268300725.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/36328876226.pdfIn PDF document text
    • http://rebornfair.com/FileData/ckfinder/files/20210901_2540800BA9E92B45.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/zunapunedivegutivuwudu.pdfIn PDF document text
    • https://rhuyscampingcar.fr/images/files/nunawazonesigejevogi.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/14806366654.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/455783f1193d7d6665409367ad65b36a/42140912348.pdfIn PDF document text
    • http://lnhaihui.com/userfiles/file/20210907091135_759700804.pdfIn PDF document text
    • https://aviseco.ro/userfiles/file/36991963968.pdfIn PDF document text
    • http://fratellilongoni.com/userfiles/files/11623387221.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=erik+h+erikson+pdfPDF 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_off0000dd98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD98 19336 bytes
SHA-256: cdd7397fbb816c26dcca503bacbda67021155cd354734425fc381dd2a0cb0baa
font_01_sfnt_off00010f92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F92 10364 bytes
SHA-256: a828837f3950d6c07128c242aa6e6a904db922fbb615447a7aa16fb22c09decd
font_02_sfnt_off000126dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1