Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c1ce3126ffd4e8…

MALICIOUS

PDF

91.1 KB Created: 2021-06-30 05:52:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 24af131a36da48f947c565f6fc8f4167 SHA-1: 04caa2631a5e4bb4b8fd315cf421cc2cb48f0d42 SHA-256: 31c1ce3126ffd4e86d084033963cbffdbffad6806d3816d1ca3a91bcba743a0c
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with many URLs pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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
  • 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://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8ac9605e7---fimibukir.pdf In PDF document text
    • http://gwtcs.org/Content/uploads/files/wukar.pdfIn PDF document text
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/rizizanamiw.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d9aa3b7cc3d---74584274924.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/81928522461.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9086850641---8258305268.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608af1c6a430f---lopareruzud.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16099d3af64abf---rogebinokuda.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/498ce9d582e2f9e67429cb22d91c6b97/zovikopigufube.pdfIn PDF document text
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/e56f60d602b2c8973596b993d6d85892/negolino.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160abc4f8d4bfd---zized.pdfIn PDF document text
    • http://teenaramainc.org/clients/875997/File/zudodatepawuwisil.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/b24fa4384747eb4b7da8b35a26361297/bosisanak.pdfIn PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16091c380bd22d---nopinabaruveworad.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/fd46d892d040149eaa961461d2734b53/92880663818.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16082c8d1367ec---tovusetuposukenirito.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/ed9a62a1ada2880ade98f38fe7784bb8/kibewinuvobogixes.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070c2863f4ca---97517293536.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/77722634734.pdfIn PDF document text
    • https://x-software.cz/data/file/25064122764.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/ervldcfrhar4c0q6e2q7prroqa/92558550786.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/texufiraxibisiverivikusuk.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/4fs3sdv9knlh42rjldbjqhhvt3/60582258435.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/96983341115.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607363b63a3e9---goxajepedifetomepixen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=gcd+of+10+and+20PDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0E 17868 bytes
SHA-256: 949d8bca2d5a22b5a40b6093ffef8af64f96579f3e967944ad841615f6e0a21a
font_01_sfnt_off00011a12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A12 16248 bytes
SHA-256: 6c7e1b754cf38ee70ad76cb780c90d71dc4ff6fc3e14eab78a91c98fc4406452
font_02_sfnt_off00012fe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FE3 10168 bytes
SHA-256: 5ac9026e9b8570c73362344da11c0e3578311c98787e43ef0cb07215f0823063
font_03_sfnt_off000146d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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