Malicious PDF — malware analysis report

Static analysis result for SHA-256 a98e590cf4d7795f…

MALICIOUS

PDF

86.0 KB Created: 2021-09-04 14:30:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 016bc594be56575e86129ac4d4115777 SHA-1: 2656d012dc407c2ecea45a0d2d0e554fcfabcb72 SHA-256: a98e590cf4d7795faefc60f746dd184db63cac7ce4ced48cfbabfe5d8657ea87
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8555

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://crysiq.ru/uplcv?utm_term=nfl+fantasy+football+cheat+sheet+pdf
    • http://thietbixanh.net/uploads/files/feladoxumodisu.pdf
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/b1321835a868083de2331027ec235c16/rifaz.pdf
    • http://muskogeeroughers1967.com/clients/9/98/9899c641331876fb313f08ec475a0443/File/6871410543.pdf
    • http://gaushalango.com/uploaded_files/userfiles/files/deder.pdf
    • http://hzjksj.com/images/upload/File/pazawoxezixo.pdf
    • http://nhuaduongnhapkhauaz.org/upload/files/55513467109.pdf
    • http://dentherapia.hu/files/file/90731539161.pdf
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/gomixomesetepip.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/fb437842648c08f923a90b3f62dc8652/sumuboraropurusewes.pdf
    • https://kermanrooz.com/img/files/35231806222.pdf
    • http://weddingdiy.cc/uploadfiles/files/20210619_061514_6450.pdf
    • http://www.tobywells.org/media/fckdir/file/66660957600.pdf
    • https://abofahed.com/userfiles/file/38712440489.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/af4de822bed4686ceb3e3e31978a793c/24895754119.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611464b38da96---xaxojuwijupawepani.pdf
    • http://mp-journal.com/media/file/65783949067.pdf
    • https://digireg.cz/upload/15003213235.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2d3179d57---89811581188.pdf
    • http://kayapaliinsaat.net/file/fuwali.pdf
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/lomobuzaxuromeki.pdf
    • https://qfse.co/images/uploaded_files/ckfinder/files/1628165416_404ccd9409.pdf
    • http://kezmosas.hu/files/file/zolijajetoko.pdf
    • https://delphin-restaurant.com/ckfinder/upload/files/27712854323.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3b40a810f1654d6a4619858c20321085/kefok.pdf
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/sabakevomepajowofoguvozek.pdf
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f41d.bin
00643edd4c97906b1eca7bd5f82c8cc334c2d7b38616681b0fde6b03608ba446
pdf-font-stream PDF embedded font (sfnt) at offset 0xF41D 10756 bytes
font_01_sfnt_off00010ca3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA3 16792 bytes
font_02_sfnt_off000124b5.bin
a1c9c5ea75eaa6f53db07749697169e41d264371d9d8cd73348da3b3a53583fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x124B5 18172 bytes