Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb557f5b45be4a72…

MALICIOUS

PDF

74.3 KB Created: 2021-09-22 16:52:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d3ec8c171215b4480bfc8ce74371f345 SHA-1: 74e0a435c2f0c1683d5aaed1ca509258c7d31e57 SHA-256: fb557f5b45be4a72c0e059cf219b604702062a222deb296e38e4ad676c9d4b45
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDFs hosted on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the ultimate destination. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall detection suggests a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://eastmanllc.net/ckfinder/userfiles/files/poxab.pdf In PDF document text
    • http://fujavietnam.com/images/Download/nasosetuxonugipojewixid.pdfIn PDF document text
    • http://one9five.com/userfiles/files/tewisogebi.pdfIn PDF document text
    • http://abwwilson.com/uploads/files/40180225347.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/8564954123.pdfIn PDF document text
    • http://okna-kursk.ru/page_edit/_samples/userfiles/files/67288370867.pdfIn PDF document text
    • https://schmitz.cz/res/file/momebevu.pdfIn PDF document text
    • http://www.parkwaytransplant.com/media_upload/upload/files/20201924662.pdfIn PDF document text
    • https://betenagro.com/sites/default/files/file/73271873526.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/20447036920.pdfIn PDF document text
    • https://ipekyolumedya.com/resim_galeri/file/jogotezelun.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/zoxofokexikaga.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/ninaba.pdfIn PDF document text
    • http://szkolaprywatnaleszno.pl/userfiles/file/44008743474.pdfIn PDF document text
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/83137586385.pdfIn PDF document text
    • http://recrute.fr/files/files/kutukelopinofunoretumewag.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/34472512966.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/58499471839.pdfIn PDF document text
    • http://dangkydoanhnghiep.org/hinhanh_fckeditor/file/23173984988.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/3edd015984035b8497d7acab8fb7e3df/jikiwefutovulazagasuza.pdfIn PDF document text
    • http://asja.ua/userfiles/file/50572344903.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/83728429062.pdfIn PDF document text
    • http://www.teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/talikorukixanolabaki.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161449f75699f8---91165660843.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+free+phone+cleaner+androidPDF 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_off0000c173.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC173 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d985.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD985 16168 bytes
SHA-256: 24233c346126e6e35ac4338ed7489343eac70bc206f7947dcf21c7b0fd086bd9
font_02_sfnt_off000102e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E7 10768 bytes
SHA-256: e2e0d5ff2e73e744a2cb7e71cfa8f6beac244bfd2f95ae56dbae1fcb89b12aea