Malicious PDF — malware analysis report

Static analysis result for SHA-256 4101bf445e77a2bd…

MALICIOUS

PDF

86.7 KB Created: 2021-06-28 15:53:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 500663eaca726e71c7702e9f41d712e9 SHA-1: ed7f17fbc442202b9cc132819bda0f25ab02fd81 SHA-256: 4101bf445e77a2bd8536b53c6cc0961eb29a153cc6cb9d6e8e0110c229449eaf
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm. The primary purpose appears to be redirecting users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/qe4p50tutfvlsc9n40nkuuj1a4/40690203033.pdf In PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/88574675887.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d3eaabb68---woxenof.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/5978130b893f91d19415e5013d5d4f41/67752533821.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/86014170944.pdfIn PDF document text
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3bd1e6e734---fatizarafogu.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/4bdd480de0ede7c7d3a873890262cf51/54255403929.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160803443dd01f---gezozekisafalusajaxaxuj.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/digefaku.pdfIn PDF document text
    • http://www.toeterloeh44.de/files/gagekozopevakuwigoderufiw.pdfIn PDF document text
    • https://finances-canada.com/wp-content/plugins/super-forms/uploads/php/files/8f9f3c1edde0ea1163174f677fb29652/sinagewewamulinoz.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160763db0df71c---19601732359.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/jiwotor.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/695b23112d942e846dfa95ee9af52acf/galarofuwomoxubuxeped.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b7aeac50055---zavifobog.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e56d3bd37---gubuw.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/185db14e831c5bb7e404594fafef5610/zomusivawipalule.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c1f4a005ae---97928996994.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/tuleziluzezajivib.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609885dd74f89---loxotakalefosiwowerefebi.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e5ae98a21---zolavosikopuzusojatovi.pdfIn PDF document text
    • https://landi-bg.com/images/file/wupekokujipikatolo.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b378d185d6---fagape.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/66639870157.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=on+wednesdays+we+wear+pink+quotePDF 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_off0000ee4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001065f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1065F 17644 bytes
SHA-256: f04490aeac9227cf6075da0b01a71554f49b6d6497b634da7b2b7a6b21e51a5c
font_02_sfnt_off0001344e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1344E 10904 bytes
SHA-256: add0b8f8b46c4ec9a556ee21416ddc4d1b526a3c551a78b533c7a35c61b49473