Malicious PDF — malware analysis report

Static analysis result for SHA-256 cad55a63a670b167…

MALICIOUS

PDF

80.6 KB Created: 2021-09-12 07:16:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0b05fd873973b736b3349aa99c7cf24e SHA-1: 50e77200b0181418f06ace5dc2c0733e7ad336f9 SHA-256: cad55a63a670b1671abb29bca0b06a0d31221b835ecb2efec21993f3a697f4cd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high volume of links to potentially disposable domains, suggesting a link farm used for distributing malicious content or phishing. Although no scripts were explicitly extracted, the presence of embedded URLs and the overall detection by security tools strongly suggest a malicious intent, likely related to spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://ulsantour.com/FileData/ckfinder/files/20210902_69B582B841F43F77.pdf In PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/53318773141.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/lelopegatopo.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16136653c8982c---mutikitolezamepepuruzet.pdfIn PDF document text
    • https://orderpoet.com/ckfinder/userfiles/files/japanudoweveparise.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/jetevorediwi.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/wuponirarufof.pdfIn PDF document text
    • http://sb-78.ru/files/file/togigexemizilejajulupep.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/23661267947.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/82925251141.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/xozawidaguwiduka.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/9c8f4fab7bc2ff352844236eafe13489/felosa.pdfIn PDF document text
    • https://sapporomn.com/userfiles/files/69589402248.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/53663456890.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/59684671812.pdfIn PDF document text
    • https://braintreeclinics.com/app/webroot/img/files/xaritiwutinazu.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/nafuribirawajaraneked.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/dexaxid.pdfIn PDF document text
    • http://zlzljc.com/uploadfile/file///2021090722313430.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/sitawosaza.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/92167889065.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210906175838717.pdfIn PDF document text
    • http://yuanjiangchem.com/upload/files/17509680663.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/fufurup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=android+tv+box+reset+button+not+workingPDF 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_off0000d6a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eeba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBA 17400 bytes
SHA-256: 2023b67ac727933e139fceb072158c73cb54f7c8c18cff4f70516c9d43c7b1c5
font_02_sfnt_off00011be1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE1 10784 bytes
SHA-256: cfeee0ee20d60780206b9edcca905a6d5c3dc5a8d8bbe0c15fd72698d16c2237