Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8aed6d63e787c74…

MALICIOUS

PDF

73.2 KB Created: 2021-09-11 01:14:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c5259a73b06a67ab5201ffb86e4e9409 SHA-1: d4722339172746e7aed9c4c32f7b23feac94f2bc SHA-256: f8aed6d63e787c748da8a6dd4a94334907a5310dfa4c91a76bdad6fe5d1f3d0a
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farm heuristics indicates an attempt to lead users to potentially harmful sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://synerhu.ru/uplcv?utm_term=film+maker+download+apk PDF link annotation
    • https://dalycity.com/wysiwygfiles/file/bamefimudosawivapix.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/657b2611638abff8a7607752c401ed8b/10098449315.pdfIn PDF document text
    • https://ismet.com.br/ckfinder/userfiles/files/rijurivumoxete.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/gorolulavubusom.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/7340556852.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138416819b45---40061043684.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/38217233494.pdfIn PDF document text
    • https://profitaler.com/UserFiles/file/2982808238.pdfIn PDF document text
    • https://itracmediav5.com/ckfinder/userfiles/files/lonokobilivij.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/teravenobanenat.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/99319203895.pdfIn PDF document text
    • http://pscemetery.com/userfiles/file/pibokadagivirutaloni.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/50425313020.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/42647318562.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161333e2960305---90084876080.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/90669543553.pdfIn PDF document text
    • https://www.jakketoes.be/ckfinder/userfiles/files/pewojupatosorekivowosap.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/pitunomuzudixijaziwemuvut.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/lipikemivefuz.pdfIn PDF document text
    • http://maxgear.cz/webpagebuilder/ckfinder/userfiles/files/63420322510.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/31129398811.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/83792809470.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/vuxaje.pdfIn PDF document text
    • http://krallarintavugu.com/upload/file/figije.pdfIn 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://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_off0000bc15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC15 10440 bytes
SHA-256: 4dc335ea4765bd4de1ff79bee785bbc06c8ac358834af49fc17d0a5eacff7d7a
font_01_sfnt_off0000d3a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A3 17028 bytes
SHA-256: f0adf61cc681fe9458ed0f7284bec2ae9e523aa2fbd73d4da3f906fc76aa9550
font_02_sfnt_off0000ff65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1