Malicious PDF — malware analysis report

Static analysis result for SHA-256 a97fdc2c7bf2e808…

MALICIOUS

PDF

83.0 KB Created: 2021-09-21 07:11:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1c70e0649ec2e1112a7fdd9f4a60b1f0 SHA-1: d78448be09da7c8e82a79c7b89fb552084483ca8 SHA-256: a97fdc2c7bf2e808c46ae433b599166766ec15fbdbad6f2fed26507d607b12cc
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, with many pointing to disposable or unknown domains, indicating a likely attempt to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://umutisi.com/umut/upload/files/rifelafixazu.pdf In PDF document text
    • https://a-pointpro.com/cms/ckfinder/userfiles/files/11513570759.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/rarigezumotudukokapixab.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/losoguv.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/21420458941.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/jixiwugufezifojudizerevex.pdfIn PDF document text
    • http://aedjtjdshbf.pretty-match.com/upload/files/famimikubunifalagi.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-20/20210920225053690053.pdfIn PDF document text
    • https://rmduncanrealty.com/userfiles/files/limibegajaveg.pdfIn PDF document text
    • https://www.serwkom.pl/plugins/ckfinder/userfiles/files/xubeduzuwibija.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/polilukemisajoxamegujig.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/wopasuvumibar.pdfIn PDF document text
    • https://lmcmanager.com/ckfinder/userfiles/files/19134178229.pdfIn PDF document text
    • http://artemon.nl/userfiles/file/51316206391.pdfIn PDF document text
    • http://ibrahimabuomira.com/ckeditor/ckfinder/userfiles/files/xakapofugafakebolewe.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/8190136834.pdfIn PDF document text
    • http://azseal.net/uploads/userfiles/file/75061397849.pdfIn PDF document text
    • https://homestayhoian.thamtuddt.com/uploads/image/files/47948344382.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/48330775327.pdfIn PDF document text
    • https://beautifulhairstore.com/upload/files/xufoganamifa.pdfIn PDF document text
    • https://mancomunidadvaldizarbe.com/userfiles/files/89324217150.pdfIn PDF document text
    • https://gallerylingard.com/uploads/file/fenifibagudugose.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=once+upon+a+time+in+hong+kong+cantonese+watch+onlinePDF 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_off0000de4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f65c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65C 17908 bytes
SHA-256: b8747cf8f6d7967024e1f39f04a37cc1e0e2b54de1c8dd7ff0bab96c60285d6e
font_02_sfnt_off0001243c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1243C 11024 bytes
SHA-256: b0fddcd27df66a271d9285eebc24dea60ee250e6459174157d265ec3e88d95ed