Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c803601b899f0fa…

MALICIOUS

PDF

77.4 KB Created: 2021-09-06 21:17:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 291f38b57ffc03663a54ad9008c00508 SHA-1: d22c6bae2ebe696f06b53cb2cf2590f7b88152b7 SHA-256: 4c803601b899f0fadffaf1393d55408f2c2754f15241adc77b7b353c75758a0f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several heuristics indicating it functions as a link farm. Notably, some links point to compromised CMS upload directories, suggesting a potential distribution point for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://akconta.com/uploads/files/bikavafewejumetewuga.pdf In PDF document text
    • http://iscyber.com/userfiles/files/65838114909.pdfIn PDF document text
    • http://salon-urody-bellis.pl/images/file/59278827340.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/74b84e2085133cfc11dade3b68bdfbf9/11335115268.pdfIn PDF document text
    • http://sun-eko.eu/files/file/saxakezib.pdfIn PDF document text
    • https://hanahana.vn/media/ftp/file/rufeza.pdfIn PDF document text
    • http://ximangsongthao.com/app/webroot/uploads/files/rufet.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/vesazovudozurijezek.pdfIn PDF document text
    • https://oglethorpeclub.org/~oglethor/UserFiles/file/sojemawelukavaxuxam.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/4542651174.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210807012754.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/maparutesitutolepo.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c62bd81391d---ketosetugemaxikusegiteb.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/81931487940.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/lesezazovobomolo.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/zaxedefemekixe.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608a74b6b5a9d---46283852247.pdfIn PDF document text
    • http://alltechsro.cz/files/36994635616.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210831112049_n72rwt.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///82675808542.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=margin+of+safety+seth+klarman+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_off0000c875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC875 11144 bytes
SHA-256: 27de5b446cff9654dd89834168f211da1ec0fe4918a51c60933eb074dba5c5bf
font_01_sfnt_off0000e21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21A 17792 bytes
SHA-256: 3f84d873e4ca0deeddb8e22fff8b523015d393899f1db641c306bdc5b5f397d2
font_02_sfnt_off0001106d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1106D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1