Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c98d1820b876541…

MALICIOUS

PDF

83.7 KB Created: 2021-08-15 02:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a7b89ab1531f0458948f63dff535429a SHA-1: bbca7cf7b1ea7a92bcb5f9f3b6ca69208a2567ee SHA-256: 4c98d1820b876541949963bad9b7630e490a2b60eb64138d55cad820cb38682f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to potentially compromised CMS upload storage. The embedded JavaScript likely facilitates the redirection or payload delivery, while the link farm aims to obscure the final destination. The presence of multiple unknown URLs suggests a broad distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://gancza-yacht.pl/userfiles/file/2172784158.pdf In PDF document text
    • http://casaatlantida.com/userfiles/file///jifoletomevori.pdfIn PDF document text
    • https://rieker-consulting.eu/files/file/5334535437.pdfIn PDF document text
    • http://businessdevelopmentcenter.pl/uploads/userfiles/files/jupuziwimuvovepe.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/17091403732.pdfIn PDF document text
    • http://spc1962reunion.com/clients/c/c5/c535eb5d361035e84cedf1152ec4da8f/File/60177964788.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/4cb98fdc842a83958c3e1459211db99f/danikuno.pdfIn PDF document text
    • https://fid-data.fr/app/webroot/uploaderfiles/40337862752.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/remobodi.pdfIn PDF document text
    • http://fxmeat.com/upload/file/07abe081af22ba488a5d7cf6c46b6c0b.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/ln2ea78ma0416eduvk3fr8ji11/naruxiponezulenopoturev.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210623132215.pdfIn PDF document text
    • http://cuatudongsaigon.vn/uploads/files/6833049722.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/6277c8da2cf9d3d1d8a577c843b5f681/fodunodalegarunotetetex.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16095d83cc681a---zenofujano.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/27863916930.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608649a76b134---74076235472.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/9845510909.pdfIn PDF document text
    • http://www.sainteuphrasia.com/www/js/ckfinder/userfiles/files/palalike.pdfIn PDF document text
    • http://www.tramag.pl/upload/file/69164698246.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/fonudebovaxun.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/87517421312.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092c3ae6c7dd---wudap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=download+alvin+and+the+chipmunks+song+homePDF link annotation
    • https://lapdonline.org/file/91840408059.pdfIn PDF document text
    • 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_off0000e389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE389 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fba0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBA0 11204 bytes
SHA-256: 6c4964d715eb6be9499abb191625fce61f6cfcfd6a317769aecf27e8ec11bbd6
font_02_sfnt_off00011579.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11579 16508 bytes
SHA-256: 8a10d64323600c7952de92a4c77138d58230f44359871bbd86d830912736b49e