Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d956aab3ae0b651…

MALICIOUS

PDF

86.0 KB Created: 2021-07-24 07:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 925a1f1b7ea2f1fdf00efe8aa34b24b8 SHA-1: a9523e6c2224d5aa309beb7826b01df124612953 SHA-256: 4d956aab3ae0b6513825f3c1c54eb0b1d5f0df28fa08e62fe07750c67f394193
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to PDF files hosted on domains that appear to be compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and link farm nature suggest it's designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://kabelkyaobuv.sk/editor_uploads/files/76755530098.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/01d23025b933a9ff1f7aaf3af19d5155/jajeroxomeromejewof.pdf
    • http://finemetal-cn.com/upload/files/begevosikejisaworedadumal.pdf
    • http://lavalnerina.it/userfiles/file/biwonagelurabevur.pdf
    • https://londonvipchauffeur.co.uk/wp-content/plugins/super-forms/uploads/php/files/3eb1403ea0414ef4caab1e75f9a5ebc7/65337187775.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8f3501ca6---45749429413.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9bfea8974---78042221295.pdf
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b9ff8e72999---98179890239.pdf
    • https://bimetoor.com/basefile/bimetoorir/files/mekixoz.pdf
    • http://thaiboxes.com/piceditor/file/palakowubo.pdf
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b04c877cffb---41269013592.pdf
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160dde4847023a---73617248301.pdf
    • http://lucann.com/Upload/file/2377239695.pdf
    • https://suma.ca/upload/editor/file/7401145545.pdf
    • https://parokisantolukas.org/Uploads/userfiles/files/97405384662.pdf
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/julubugusazosukawiga.pdf
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/37s2g7gsgvkmdaqvv3m178f2jt/20490863986.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/a20172596122f73e0abcbdd9feaecd6f/silixibokomixogodalenag.pdf
    • http://presssimayeshahr.ir/pic/file/75272717785.pdf
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/afd0ff305f2907d70382ac51bf031c1d/93020308226.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a77359e729c---wodexuruluvetidanuzedav.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=maths+3eme+exercices+corrig%C3%A9s+pdf
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebf0.bin
4ae33abd40a8572c53e11f66f87bdc1c922b4d7c8c24304ab9d448c8e9345f23
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF0 16700 bytes
font_01_sfnt_off00011533.bin
8fba2768a959d2507b06dbbabbb1ed0749b4ca7a9370ee9492acda097faf8258
pdf-font-stream PDF embedded font (sfnt) at offset 0x11533 11340 bytes
font_02_sfnt_off00012f74.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F74 16792 bytes