Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a1d311f39f6ca10…

MALICIOUS

PDF

97.7 KB Created: 2021-08-06 12:26:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f9861558959e5e60cf8bec98b7b8edd9 SHA-1: 830e78c710db6a253922466287e990bceaafea96 SHA-256: 5a1d311f39f6ca10359a4e03ceeb220dd4801b4d3f22adf3d35a31440bb85c2b
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and the PDF contains numerous links pointing to potentially compromised or disposable hosting sites. These links are likely intended to redirect users to malicious content or phishing pages. The presence of multiple PDF link farm heuristics further supports the conclusion that this document is designed to distribute or host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 5

  • 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://twfern.org/upload/ckfinder_temp/files/20210617105856.pdf In PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160c729802a8b4---rivipalidubopelerilolage.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/xeguv.pdfIn PDF document text
    • http://ankaser.com/userfiles/file/78734567842.pdfIn PDF document text
    • https://mobilityservices.it/file/roninebajiwitu.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a92ba0a0adc---jazelinak.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/hc67nslecbtmdn97f5ndhav8i1/18551546166.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/530t87iafda9ks2v4bk5bqljcu/fuwavovitufaxulixo.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/jakise.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/d07689a43760cc5d8b86c221e1295434/fofamajifoguvosazesigul.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16103a3b955771---49434675913.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161031140d06fb---duxabowo.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/fijemomuv.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/ad6c91299aa7fd321c45afb34b0d0fa8/28723349367.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/38399414.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/fa6ato37leqjc618h019uprfm6/26221974085.pdfIn PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/461cf1175ac8fe5fb5ece4f13ace5c0a/dotekeloboxomimurupozumab.pdfIn PDF document text
    • http://jonkmp.nl/img/cms/file/wakudaxakikebo.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/givexuvasobudinuzuju.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/die02u3p4mfl6hopr6916hljqk/6336806237.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/62a6dadebdaa21f9e3ad6e3a83327894/lefizidanuviz.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/nuvemotutazexetatovamu.pdfIn PDF document text
    • http://betaempire.com/uploads/userfiles/file/file/todeg.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610635b1eabc1---98539104038.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=linear+algebra+and+its+applications+strang+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_off00011b08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B08 10892 bytes
SHA-256: 98f18532972fed0f04f555f4f2b5ea106b9612ed9d1559d8e4daa4a3c5b001ea
font_01_sfnt_off000133df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133DF 17276 bytes
SHA-256: 7944eac4cd31635921b6ae00daaccf5f82bfd9cdc31d0512f76e4320983a664e
font_02_sfnt_off00016094.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16094 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1