Malicious PDF — malware analysis report

Static analysis result for SHA-256 b996d8365f3c618c…

MALICIOUS

PDF

85.2 KB Created: 2021-09-15 14:24:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: dee68507a5b4001227268939982ed5ba SHA-1: cd42bd2a2d696bbc47e7d8a690042c75f3a4ba68 SHA-256: b996d8365f3c618c83fd1430480f22abe8ae19c53e631a774715b49f61aa6f40
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://chcial.ru/uplcv?utm_term=the+walking+dead+game+android PDF link annotation
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/s4l105mr0q23ffbnr934hmv35f/buvunomobinubo.pdfIn PDF document text
    • https://datatech-int.com/userfiles/file/34139302324.pdfIn PDF document text
    • http://webbuilders.com/files/file/56044847069.pdfIn PDF document text
    • http://haphadoor.com/upload/files/mejiribisubetelirepinos.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/73901041572.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/86172109765.pdfIn PDF document text
    • http://mkpstroitel.ru/upload/files/jimubedewiba.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7cefa607a---kobapolebixiwoju.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/32969041888.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131511ce2329---mubosixanusibeliwujiwane.pdfIn PDF document text
    • http://columb-sklep.pl/userfiles/file/vivejuxegixojetiguteku.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/1594753752.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/38444847576.pdfIn PDF document text
    • http://gtlitalia.com/userfiles/files/difenovimekatumawud.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614152c0e49ea---gefurowukufag.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16141c0efe1e9a---tedumibefudofopip.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210901125008.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/86745040671.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///43731953327.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210907020529.pdfIn PDF document text
    • https://diamond-marketing.cz/soubory/94759534199.pdfIn PDF document text
    • https://livresdarts.com/ckfinder/userfiles/files/jasowozexemujeme.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/zexiwuwibo.pdfIn PDF document text
    • https://szekszardportal.hu/userfiles/file/18851977588.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents/files/70778543872.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/dewarelizefu.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_off0000eb8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB8C 16824 bytes
SHA-256: 7c23faae3b1967620b3c3311e7c70dd54256421caf63b01faec7a9ab5a8b9fed
font_01_sfnt_off000116f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F0B 10572 bytes
SHA-256: 923c0c5406baedf863c1bd87887a0d236ef4e01dfb9d8a050a40c52b88345516