Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3ee758495bdb1c9…

MALICIOUS

PDF

72.9 KB Created: 2021-09-17 01:23:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bc589a4a6e33d6c2e82ebdb95cd2dc96 SHA-1: 1e1725a2860f0abd559db6a201a7b388a4bc0d13 SHA-256: c3ee758495bdb1c908d75d3a980433810e4886e78509b192af5de2962b5a238b
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous embedded URLs, many of which point to a link farm hosted on disposable domains, a common tactic for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://veterinariacasettamattei.it/userfiles/files/zeritaf.pdf In PDF document text
    • http://around-sicily.net/userfiles/file/53032885163.pdfIn PDF document text
    • http://www.neoneofitou.com/ckfinder/userfiles/files/24213652036.pdfIn PDF document text
    • http://sb-78.ru/files/file/jeleripevowunutesasovofux.pdfIn PDF document text
    • http://laboratorioshamalab.com/userfiles/file/34865131811.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/pazizawimuwajig.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/45502008931.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/retili.pdfIn PDF document text
    • https://lazerom.pro/media/file/laselurisu.pdfIn PDF document text
    • https://ringid.vn/ckfinder/userfiles/files/wuvefudujikeruremibaseriw.pdfIn PDF document text
    • http://incomingmakedonia.com/files/files/20453843325.pdfIn PDF document text
    • http://sintjorisparochie.nl/userfiles/file/84118340999.pdfIn PDF document text
    • http://jia-longsofa.com/uploadpic/jialong151126/files/202109170600375661.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141289345097---rijebadokuxuzakikivis.pdfIn PDF document text
    • http://zoscm.zohukum.com/ckfinder/userfiles/files/xejexogikasi.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/labupakaxesawonawuduf.pdfIn PDF document text
    • https://epponline.com/mentorfinancial/page_images/file/pefuliroforuvilenilit.pdfIn PDF document text
    • http://eurolocal.info/sites/default/files/images/file/xavukapesoravarabobokup.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/28302496090.pdfIn PDF document text
    • https://vroa.pl/chplusfiles/file/zetuv.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///72488947256.pdfIn PDF document text
    • http://inlovehuahin.com/file_media/file_image/file/banofemalaluwudadulekobuk.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210914183134.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/fuzifuxamukobulite.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/73958779994.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=9+std+biology+textbookPDF 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_off0000bb68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB68 16804 bytes
SHA-256: c50c57ea6d50d882236bb54a7e61a0b6a31fe2f06f84157f1f0939da7a68353a
font_01_sfnt_off0000e63d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE63D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE54 10576 bytes
SHA-256: db155e0982798403b5858f51ba8e36c6a278a597f2d4f92b94eaa1cf2296fd3e