Malicious PDF — malware analysis report

Static analysis result for SHA-256 8de791ad09522ddc…

MALICIOUS

PDF

85.6 KB Created: 2021-09-10 10:17:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1c77392f497148d6a5602f54aa32ffcf SHA-1: a158e069a326dc0882a0012560e6ec74ce58b383 SHA-256: 8de791ad09522ddc8cf0c76061dbc374d5e6ec03d86b4fda65de04c1acf37f84
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous embedded URLs that point to disposable hosting and function as a link farm, a common tactic for phishing or distributing further malware. The presence of these links and the overall structure strongly suggest a malicious document designed to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://queure.ru/uplcv?utm_term=critical+ops+mod+apk+download PDF link annotation
    • http://kalkulacka-hypo.cz/userfiles/files/10656899115.pdfIn PDF document text
    • https://hongdung.vn/ckeditor/images/files/xukereretofijusujugosu.pdfIn PDF document text
    • http://to-tuong.com/media/ckfinder/files/15289961876.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/somup.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/82574608098.pdfIn PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/beporerejabodubigig.pdfIn PDF document text
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27061332945.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613289d51082d---vidunex.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/wetenif.pdfIn PDF document text
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/91988979257.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109041837237630.pdfIn PDF document text
    • https://bczenekar.hu/files/file/62843066973.pdfIn PDF document text
    • http://rld-carbon.com/file/bozumufe.pdfIn PDF document text
    • http://webursitet.org/Files/file/semafekefifejoj.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/31377573054.pdfIn PDF document text
    • https://jeneifogaszat.hu/cikkdata/files/73229006987.pdfIn PDF document text
    • https://giga-tronics.com/userfiles/files/jusonamiz.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/tizudop.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/xatifofefeva.pdfIn PDF document text
    • https://alpinebadmintonacademy.com/ckfinder/userfiles/files/wekukan.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/rosowajus.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/58496249478.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/debizefom.pdfIn PDF document text
    • http://opsir.eu/files/file/83263507670.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_off0000e79c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE79C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAE 18804 bytes
SHA-256: e0b6097126223aeb241ded5eeef9cfb56da91419904e9720c5a065a429c43927
font_02_sfnt_off00013023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13023 10752 bytes
SHA-256: 05c7276820befe72548208d85ca839f20638f26bb50db36dd43518206bada58d