Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a484ec077ccc10…

MALICIOUS

PDF

72.0 KB Created: 2021-06-08 07:45:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d868774c3665ec7c6f6ff582aac2a87d SHA-1: 2813153a44735877bd995fbf8af31dfb0cb1c717 SHA-256: 91a484ec077ccc10ec40223f9867f4c071f3210f468c794590f386a06ff9965f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to distribute malware. The presence of a 'download' lure further supports this, indicating the document's purpose is to trick users into downloading a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crewmak.ru/uplcv?utm_term=section+3+guided+reading+and+review+basic+concepts+of+democracy+worksheet
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/2be1brea4vijcurma8knfrm515/zopemodi.pdf
    • http://fullcolorspandoeken.nl/userfiles/file/87930010313.pdf
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/296e9495c321d9a0e0a79f4008d9af50/kegotavujumatedotanusowi.pdf
    • http://tamlaproject.com/userData/board/file/bamojupovutimepojama.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d266160cb2---dapugevagow.pdf
    • https://alianzatours.com/imagenes/file/bufivot.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096435f23b31---87398460542.pdf
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f46478c327---8122337007.pdf
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/01553702b2624225405d2fe0723556d6/fekivasuzategijebuneguv.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0f7f339ae---xosuzefukemugazuniligemop.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608307d24c007---72162578576.pdf
    • http://ahcxdq.com/uploads/file/020355282092.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b350f74a2e2---55095749578.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/f5f9aecf3d08aab0789b2272d8b770cd/bikugeludolusidozezesuvoj.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160904a424f5cd---jekakijodokawalitebu.pdf
    • http://aylincinarli.com/fckfiles/file/xiwuverekakumupor.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608acc569fbf6---dalobitamajusazafo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8df.bin
071c177ecc2e1b49cdf03479fca9cd6684f56665b062b6f3f93a7c2c54aae72e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DF 6264 bytes
font_01_sfnt_off0000ee1d.bin
2d247dda3bd9650b4c9645bc9eae0bd8f291567aa4d7922012aad66ea5ce804c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE1D 10584 bytes