Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fa8b4e1f40c1c53…

MALICIOUS

PDF

89.7 KB Created: 2021-06-28 23:21:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0e1a2817ae62930616a437dcc5636ff2 SHA-1: 4f8b54a8b7bad6c807fbd0851cf423ee9edb5bf5 SHA-256: 4fa8b4e1f40c1c530b583da600d358329501720690f0ce860e3b6199881ca48c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites. The presence of numerous external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://archi1919.com/smlclub-files/file/61072416741.pdf In PDF document text
    • https://zenkenmoshi.info/images/files/file/nepodofajevedebuzufev.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606faccdd6959---lexobifaxigigewu.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077ab5fa0bcd---79096574588.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/fevizutitalifamalasaxe.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/g3jqhjjlervdqu2pua602qts7k/kadetanafimix.pdfIn PDF document text
    • https://oliogalanis.com/file/35344207155.pdfIn PDF document text
    • https://uniontend.com/userfiles/files/31027295399.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096728463050---sutudeti.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070fa1f21e21.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/ud0jehh7h34a6om8jqngu49h9p/79178930059.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/0d9b97422a2b67cf2cb9a9b4702fec01/42113716299.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/58896517447.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad769628aea---vevoza.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/ziwazisutovunarapa.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/76775137041.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/e4277d8895b08b7d0ac9fa1a5fe4609c/88939410459.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/nfge4crq0raga51hh5v5ol0ib6/kokejixumaginomewinaweg.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2e02e94d9---wubewojeji.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/559d855637ded8422b2d015cd217ed86/28879947895.pdfIn PDF document text
    • http://uctodane.cz/UserFiles/File/resokegesuvapagop.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ab2d44e5a---xozevijizasowixorimuti.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/449d4c60c446afe46914e829cc143135/69393924519.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160976ab90995a---42473474308.pdfIn PDF document text
    • http://bigpictureresources.com/userfilesbigpicture/file/52200935005.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=famous+latin+american+artistsPDF 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_off0000f899.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF899 19008 bytes
SHA-256: 772f83ab33ca101420919fe9636d02d2fa808238fc56064c40481fb9d5027657
font_01_sfnt_off0001296b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1296B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014182.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14182 10468 bytes
SHA-256: aaf0018c83667b26f0dbe94864100bc2d5b80f0e5298a3bb5ca9541f25cb47ba