Malicious PDF — malware analysis report

Static analysis result for SHA-256 431854b7d0bf5d56…

MALICIOUS

PDF

89.8 KB Created: 2021-09-06 01:08:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fcdc390d61f30d7ce0127dcc04e41dec SHA-1: 88a22071fb1e9f22f9eb87bf5299c3b3569912ff SHA-256: 431854b7d0bf5d5610ba137f5845a9ba90958aa652698ed9f713baf584a33fdc
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to potentially compromised websites and disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://steelbo.com/uploads/admins/u0/files/20210724105054.pdf In PDF document text
    • http://pho32shabu.com/uploads/files/kabuzanof.pdfIn PDF document text
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/57634973163.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ee8ae654b94---kulusutimexedikumeb.pdfIn PDF document text
    • https://repare-ton-smartphone.com/userfiles/file/nutobozovo.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/2157ced4aef3d715425cc7126d1865b8/50494137478.pdfIn PDF document text
    • http://autohondl.cz/userfiles/file/39889543361.pdfIn PDF document text
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/javadefemilokunutadesiw.pdfIn PDF document text
    • http://winso.tw/userfiles/file/76534718088.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021080722573573499.pdfIn PDF document text
    • http://oletrans.sk/editor_uploads/files/41540192780.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/gusatepasokidoxomamuj.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/vepebegexenoxefadosapaz.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098cef7b8e87---zagewukapikawifutoj.pdfIn PDF document text
    • http://1hozain.ru/files/userfiles/files/worozodunofenebojiteduda.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/31437378977.pdfIn PDF document text
    • https://imaggu.com/ci/userfiles/files/4166154830.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/28cc1vpafdfau1ufdg34j31glo/37497905871.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a050b25c0cc---vuranujuwunoxotutoda.pdfIn PDF document text
    • http://kanstm.com/ckupload/files/bawaximikixikosi.pdfIn PDF document text
    • https://ocw.tw/uploads/files/69399216393.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160884929abdac---befojobetefujiwoxutonaze.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/puzipisarad.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b757a6f0689---detojuberalinebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=homonimia+y+paronimia+pdfPDF 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_off0000f09b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000108b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B2 10320 bytes
SHA-256: a7beca73a9f2f5d630f2a683542291585363f1ebc0d3733bc97cb944cede8214
font_02_sfnt_off00011fca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCA 22892 bytes
SHA-256: d9333004aca6b2397dfd6fde54986836485c0b8ec9168c9b8f4d536e7988b680

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