Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cf03682583bcf4d…

MALICIOUS

PDF

70.3 KB Created: 2021-09-06 20:45:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6c191e80f3be7a4a70e9fa7ff6946edf SHA-1: afb6ca36afd1e9f21016c58335871fc5e6655e39 SHA-256: 4cf03682583bcf4d1fa27c40e07ba9b69039165efc5ba6c4a7a917d0bfa7fc20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of a phishing or SEO poisoning attack, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://infrive.ru/uplcv?utm_term=jenn+air+gas+cooktop+repair+manual
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/7daf264327ea45208df67c37ad386374/sukotegodebuzibim.pdf
    • http://agierresrl.it/userfiles/files/sijefivirefopa.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160cdc062336aa---mamojuzepanabazirukezato.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c21bddac3d6---78213651170.pdf
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/xiregesaz.pdf
    • http://refah4ter.info/basefile/hotelrefah4terir/files/guvagufomuziz.pdf
    • http://resetimpianti.it/reset/public/file/83452596510.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609767082c1f9---56045576971.pdf
    • https://autopratichesas.it/file/99275985045.pdf
    • http://ramenhajimetustin.com/uploads/files/81026964381.pdf
    • http://aaz.sk/editor_uploads/files/50495685230.pdf
    • http://indel.sk/userfiles/file/rupavekil.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077e1aa0ad80---67811686195.pdf
    • https://kede.org/userfiles/file/sedawibu.pdf
    • http://cymrozgreatdanes.com/clients/1/1a/1a407d8ccac5525c71aaafb6b4664123/File/42824258450.pdf
    • http://hotelbelleepoque.bg/userfiles/file/63995740370.pdf
    • http://vodnik48.ru/content/file/lezewoxunusuzutonisowe.pdf
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/gajurokituk.pdf
    • https://autoprofi.ua/userfiles/file/57087440130.pdf
    • http://decoworld.in/dayafter/uploadimages/newsimages/file/kafaponesosuzufaku.pdf
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/92f1ef75e749e8e32a8745b90e1c0c33/rimalivisuvuvezawonelobap.pdf
    • https://susta.vn/userfiles/file/gujunakokuzinuziji.pdf
    • https://suma.ca/upload/editor/file/nigetegisajabe.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_off0000b39d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB39D 16792 bytes
font_01_sfnt_off0000cbaf.bin
586c3a0fc34582260152778b0e68fe4ec76109612f47149fc210f831cb2450f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xCBAF 15316 bytes
font_02_sfnt_off0000f280.bin
07bdab3936094091b31da54b34fbccca6979034a9ba8c4a699f774f7f7899dc8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF280 10900 bytes