Malicious PDF — malware analysis report

Static analysis result for SHA-256 655635a20eb728d5…

MALICIOUS

PDF

80.0 KB Created: 2021-06-17 07:50:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 5e3d91f927758949907617a5e440cf2d SHA-1: 26d785efb5a34aaa00f502408e0009ab32d1390c SHA-256: 655635a20eb728d5f43fa39c915653ed48dfb26279c12ddc0c8ec632016f428b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The document contains a link farm pointing to numerous compromised WordPress upload directories and other domains, suggesting an attempt to distribute malicious content or phish for information. The presence of embedded URLs and the nature of the heuristics strongly indicate a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://irlanc.ru/uplcv?utm_term=new+prague+school+district+jobs PDF link annotation
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bfdbba1731a---kinejowibaniwibirotetem.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609841a142572---8591566028.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/291601097205.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607934792a781---62891518252.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/nifinurenidi.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf98138116---54980970349.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a88f01e171d---donizepogabipoke.pdfIn PDF document text
    • https://dietacud.eu/upload/file/sewanuzumuram.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce66e0f818---gijapopebig.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/247olhlqs7n576p2u9ve4i5pk6/29397039596.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/zosilipibopawobabanomubur.pdfIn PDF document text
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/a4cb9caade9dcd045059ddd69b2acb3f/womunutikapelepedisojap.pdfIn PDF document text
    • https://aronabritcan.com/userfiles/file/92753308307.pdfIn PDF document text
    • https://annjulieskarpmo.com/userfiles/file/gimiv.pdfIn PDF document text
    • http://hotelsandmartin.cz/files/file/2154021456.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/90080212122.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/htb5llrltssnokm5cd9qlgtltc/16117346054.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f730.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF730 5612 bytes
SHA-256: 64db713c9baa85474272976ee35de8c97775d5543f4f3b68f0eec2f465303cf9
font_01_sfnt_off00010a53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A53 12344 bytes
SHA-256: 3b0de0af748be56e155fea5cc868d7dd7785416117d80e724045be8a5dfe5f74