Malicious PDF — malware analysis report

Static analysis result for SHA-256 d48c4b1bd585fdd1…

MALICIOUS

PDF

74.1 KB Created: 2021-09-12 18:24:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 86c77b8206c24fc48b704cc7ccc6f1e4 SHA-1: add9b41c5a0a6d659d8b0eeb51f787a6b995fd9f SHA-256: d48c4b1bd585fdd12072a11bd339e50360b1bc0537eb177475f8be6ffc32a22e
156 Risk Score

Malware Insights

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

The PDF contains a link farm, with numerous URLs pointing to external sites, some of which are hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://tckontrola.hr/files/3160933465.pdf In PDF document text
    • https://rais.bg/uploads/file/96455985917.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16135e49117128---84235134631.pdfIn PDF document text
    • https://abicecream.ru/ckfinder/userfiles/files/gisepavalewov.pdfIn PDF document text
    • https://generalaudit.pl/eurostyl/photos/file/78222084224.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/wirofev.pdfIn PDF document text
    • https://mldom.xyz/web/img/podborky/files/ranotirozivugowizovek.pdfIn PDF document text
    • http://gusanhightec.com/userData/board/file/57493776926.pdfIn PDF document text
    • http://fructusartis.com/i/File/luzolizok.pdfIn PDF document text
    • http://directopinion.biz/uploads/FCK_files/file/tizekiwemude.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/2cb692bc3fab46240ab1c8d20391ef9a/33289975932.pdfIn PDF document text
    • http://ufcnagykanizsa.hu/userfiles/file/7434460818.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/62765135029.pdfIn PDF document text
    • http://quiltingacademy.net/fckeditor/userfiles/file/11190516434.pdfIn PDF document text
    • http://londonjip.com/userData/board/file/14422724849.pdfIn PDF document text
    • http://gulfcoastlist.com/userfiles/file/88329485023.pdfIn PDF document text
    • http://safetruck.gr/images/file/jurizaxebikilebukolem.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/wamuxapovo.pdfIn PDF document text
    • https://samsungklimalar.com/upload/ckfinder/files/fuwukiro.pdfIn PDF document text
    • http://zsdbiopharm.com/upload/files/mebametobesufolo.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-3/20210903042259337119.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/fajikifazefabaz.pdfIn PDF document text
    • http://vuason.vn/upload/files/pilizizejo.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/pulolosamusisabi.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16130cf2565be4---75697296455.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=toca+life+world+vacation+apkPDF 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_off0000c018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC018 16300 bytes
SHA-256: 884e682b890c5aa183f9d626fca27ce5e6a2f61149329b3e1afbcd460722542a
font_01_sfnt_off0000e9f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001020f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1020F 10652 bytes
SHA-256: 35d9273a568f5fe3ecc8126ddb27615f36853dcf848381f656331effb58ba1c3