Malicious PDF — malware analysis report

Static analysis result for SHA-256 f770941821c0d4b0…

MALICIOUS

PDF

71.2 KB Created: 2021-09-11 11:05:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 20a0f2960f8c8a5c99f4a348710c07e4 SHA-1: 0a7cb92c177b64eadfb9d119fed56118455dac96 SHA-256: f770941821c0d4b037e96ba46607391d2c70a6bbd4ff6f9f7b0a620e4fcf3535
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it is designed to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://komunalno.vrgorac.hr/files/jugokapalepanozexin.pdf In PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/5tm6h4m60jq4n7pm2u3352p8a6/25704040838.pdfIn PDF document text
    • https://saglamahsapkutu.com/img/editor/image/file/nuzatizuzefax.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/vejubabuw.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/zudufakofiwomenemipi.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/72021275673.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/68298503779.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/purasivukupesadugovitoso.pdfIn PDF document text
    • http://unibox.lv/files/text/jotofavamugozaxag.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202109/file/lagijususegomikar.pdfIn PDF document text
    • https://digireg.ru/upload/lidumokiwe.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6133dd57d---34504277546.pdfIn PDF document text
    • http://hutbephottaihaiphong24h.com/upload/files/34330517740.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/57111543779.pdfIn PDF document text
    • http://trungtamdaykem.vn/Images_upload/files/87147791183.pdfIn PDF document text
    • http://vswet.ru/f/17257900804.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/90528229549.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/26902608847.pdfIn PDF document text
    • https://corcreation.twbiz.me/data/fckeditor/files/20210904_151639.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/45414523168.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/61629431492.pdfIn PDF document text
    • http://olynskiconstruction.com/pics/file/14682690421.pdfIn PDF document text
    • http://acunambalaj.com/adenoto/upload/files/bexukemiwelesotazoru.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/63109277177.pdfIn PDF document text
    • http://remont-elektro.eu/archiv/file/nuripokalud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=iron+chest+transporterPDF 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_off0000b5b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCB 10284 bytes
SHA-256: c97adaf1b08d730da6cb48b264034572afe0c95b4371fbd840c28e3c53e8e489
font_02_sfnt_off0000e4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4E1 16104 bytes
SHA-256: 297d2c128936f01389fb5502c4438c653d78740ac87b44143616bf742eb05a76