Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef1a2ae5397bd88…

MALICIOUS

PDF

86.7 KB Created: 2021-09-19 07:28:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f0820d0430836b70d68ebd23274c0038 SHA-1: 222a41908d8cb48eb43267d60987dd80474027b6 SHA-256: cef1a2ae5397bd8844020c91ac75e21674ad4360739882a318415e44cfc367f4
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://vasutaszeneiskola.hu/ckfinder/userfiles/files/tojitofugamonalogo.pdf In PDF document text
    • http://sakra.sk/storage/file/95931390313.pdfIn PDF document text
    • http://colorfulmedia.de/fotki/fotki/file/xafilivazemobefelisume.pdfIn PDF document text
    • https://gkscam.com/userfiles/file/wojowasobezewiniwuterimet.pdfIn PDF document text
    • https://lyubomiradineva.com/files/file/40270936541.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/redufelaxiruwikake.pdfIn PDF document text
    • http://acutecardio.ru/sadm_files/dulezeg.pdfIn PDF document text
    • http://king-tableware.com/uploads/files/202109161222548404.pdfIn PDF document text
    • https://aspirecambodia-edu.org/userfiles/file/9724048395.pdfIn PDF document text
    • http://perfect-gallery.com/userfiles/file/77459199026.pdfIn PDF document text
    • https://maintogelonline2.org/contents/files/tifalifonifagenefa.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/xogozulenavuniravej.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/pobamofiwexebem.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/dozekiraluno.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136a89e7deb4---misefuta.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/91611265687.pdfIn PDF document text
    • http://hotechike.com/files/files/felujum.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/lobojigagagibud.pdfIn PDF document text
    • http://rideco.hu/upload/file/xevutina.pdfIn PDF document text
    • http://abpjse.news-read.com/upload/files/95986783212.pdfIn PDF document text
    • http://packturf.fr/files/15650609102.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/cf5e43a588ce03b415e5b856065e1ae2/1974615511.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/99008078922.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/24458768970.pdfIn PDF document text
    • http://wuxihemei.com/ckfinder/userfiles/files/20210919_054413.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/fb396d282b8c4a1301b23e6da8bb90e7/jaforilez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=dragon+ball+xenoverse+1+apk+downloadPDF 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_off0000e953.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE953 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10165 19100 bytes
SHA-256: 50466e3991552cb43d5fd975e13a9af31fa8a00795e37cc674b0e62bf49a93e9
font_02_sfnt_off000133f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133F1 10916 bytes
SHA-256: 81dcbe7e812de25f8cbc303c029597cf095c535912d56e5727be88136d5009fd