Malicious PDF — malware analysis report

Static analysis result for SHA-256 9dbcb152f8539a99…

MALICIOUS

PDF

83.6 KB Created: 2021-09-16 23:57:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: efefff26b4d6f397ff9617672566e0b7 SHA-1: 06bd3f49bc258ecd42fe372c5cece1c654e4f64d SHA-256: 9dbcb152f8539a99184ef2f0f124a328a27a20bad144afbabb44e030ba492f2b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised WordPress upload storage. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the structure suggests a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://narnivet.com/userfiles/files/90632813093.pdf In PDF document text
    • https://securitydm.eu/slicice/file/41748610450.pdfIn PDF document text
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/zozigadudowinatuvav.pdfIn PDF document text
    • http://megatex-plast.ru/pub/file/lalebawaxozogetin.pdfIn PDF document text
    • https://pchome.uzai.ca/upload/files/39795274535.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/26678854955.pdfIn PDF document text
    • http://botaierpharm.com/upload/files/juwuxodogebowosut.pdfIn PDF document text
    • http://www.mediagrand.hu/data/editorfile/62645209327.pdfIn PDF document text
    • http://mfo-fond.ru/ckeditor/ckfinder/userfiles/Images/files/jepokupomigevafomeben.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/95a1188b28c89231a54ae48d820250b3/3648051280.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/13061477533.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/2705633028.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/najumoz.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/85022351553.pdfIn PDF document text
    • https://alhurwallpaper.com/Files/files/rodof.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16138cd11f2ef3---82565965310.pdfIn PDF document text
    • http://yourhandmadeitems.com/userfiles/file/30443960052.pdfIn PDF document text
    • http://blankheich.de/images/uploads/file/fazigalakimewuwogezokakuv.pdfIn PDF document text
    • https://stockbauer.hu/uploads/file/miwewatutisedufanik.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/69151179377.pdfIn PDF document text
    • http://kammed.com/userfiles/file/77714093508.pdfIn PDF document text
    • http://klawiatury-foliowe.pl/_data/file/fasires.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/389rj5snci9hq2a2uo43kv740s/58185008248.pdfIn PDF document text
    • http://hoachathoanggia.com/userfiles/file/12969423747.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=miracast+apk+modPDF 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_off0000dd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7B 19344 bytes
SHA-256: 45096c2e214731427ac408b5c9f819969f1b37c2d94445a733bdef49916cd7ce
font_01_sfnt_off000110a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A2 10480 bytes
SHA-256: 4883f865594660a8823d3e5ae50400ec6de8adba1f371900aa11801ab32b40b7
font_02_sfnt_off00012883.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12883 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1