Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9d1bc598338b7c8…

MALICIOUS

PDF

83.5 KB Created: 2021-06-25 16:11:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 1f0e89a720648ba1ffc2c2e9700ab5b4 SHA-1: d58635d59bbe5025b959465166487a3a3699f2d3 SHA-256: c9d1bc598338b7c833566d6f07e3dd2fa0132b67a0ab877240b7aa0d0ffbf2fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a link farm pointing to compromised WordPress upload storage, suggesting an attempt to redirect users to malicious content. The presence of external URIs and the nature of the link farm indicate a phishing or malware distribution attempt.

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://heatingboiler.ca/fck_upload/file/databifaxesesixu.pdf In PDF document text
    • https://vietfun.com.vn/wp-content/plugins/super-forms/uploads/php/files/hecibdlaq08gp09n5ts9slbkm3/gepodowapo.pdfIn PDF document text
    • http://dermaktif.com/imgup/file/narolubatimu.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/tk4vhidie429n3rm0g14fci6jp/13687381967.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609896b5d5617---dakowonugalejizufuzavej.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/wabiwiduvijukuzufitis.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/7a70cco3e3nau9b9u34brj8753/gukesiraxopepo.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/vq75g8jesfdmkoljh7fuhej25c/topafo.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/d08ed8ce75773e5c7dd05b97b6650802/26803337595.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/bf7f53ff4fa5c7442e2cff1fa5ae2b3c/rozune.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072a604a5b04---wisugufok.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/a7bcca84489697141426ef7dc33cce54/60099351445.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160730171913f0---vefurilefifim.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/38591785036.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021614741437384.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/5ja0udued9vjqen662qd2f4utc/vamujomevizaninaxo.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/ac32effdeee1c545052303e641b0c2ae/debunufemoxijujade.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+play+stablefordPDF 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_off0000e36c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE36C 10628 bytes
SHA-256: 28e3ca3314cefc442758cc6d5474cfeb0fe9e9714e80533e567b88d0c5a6f904
font_01_sfnt_off0000fbbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBBE 17428 bytes
SHA-256: 6a7f43ab6336d9ca793b4f024f560159f4649a95532896d6ff480ef9148e0dbe
font_02_sfnt_off0001297b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1297B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1