Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f5a11762e059a98…

MALICIOUS

PDF

79.6 KB Created: 2021-08-31 00:49:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6bfbe73d66bc93183bc6d7ba1a279134 SHA-1: 5b36eec4f9780a91f00f098237619bf7c6bf63e1 SHA-256: 8f5a11762e059a98e40e9de362d9710f454003c52a2f803438e990145618832a
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating it's likely a phishing or trojan delivery mechanism. It functions as a link farm, presenting numerous URLs that point to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The PDF structure itself does not contain readable content, but the heuristics strongly suggest a malicious intent through its extensive use of external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ad878875d2e---97513783414.pdf In PDF document text
    • https://anfauglir.com/images/file/90702024203.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fec71af33e4---92171242970.pdfIn PDF document text
    • http://grandinspirations.com/clients/75274/File/fuduxu.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/207f117a2a6ccde724ea07ade9899d4a/92077228207.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/121611078741.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1656af72e---repowujipokaxumusojow.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/18242750272.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///8379188287.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/dovape.pdfIn PDF document text
    • http://zajazd-broadway.pl/galeria/file/rofep.pdfIn PDF document text
    • http://ore-processing.ru/d/files/pokezekigobufokav.pdfIn PDF document text
    • http://www.ujepites.hu/userfiles/files/1770525675.pdfIn PDF document text
    • http://shop-cartuning.pl/userfiles/file/91096252129.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/nebaxox.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/bc9ff797a06233f69003a7c5ed099748/votetewomulukerebop.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/1917c445ae48c8ec3250ec367a78e70b/11912223160.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/28363629880.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/girozasomu.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160fb1b6c44c01---92767732627.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/vewal.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160903b052aad8---62770989317.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c87f4259437---25576344921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=mcneely+law+officePDF 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_off0000d31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2C 17904 bytes
SHA-256: dc60bddbc58fc3dfa3ebaad8f2d9e581c7e8f823d6598f004839b0aa9cec41af
font_02_sfnt_off000118f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118F8 10156 bytes
SHA-256: 9dcec717e39920cb87047c67622b4b2c513640c3e6ba97001f28558b9f337124