Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1b53360ebb051dd…

MALICIOUS

PDF

89.2 KB Created: 2021-06-27 13:48:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5cc1bc659fbe3b8b0c3e2eb776b74442 SHA-1: 6f48714d746128f53b2f033ea09e929ce79f3217 SHA-256: b1b53360ebb051dd0cbbff81acd919af5a7276ed82f3ba86276eb138f5115916
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM strongly suggests the PDF's primary function is to act as a lure to these external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://crewmak.ru/uplcv?utm_term=newspaper+today+in+english+pdf
    • https://terminal.hr/userfiles/file/mawulogepo.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e5bf53c5b1---40802251986.pdf
    • http://www.kymenhome-etsinta.net/tiedostot/files/41692282680.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086edea274c0---91890638703.pdf
    • http://amdind.com/userfiles/file/94221799791.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae704c57d88---gusiso.pdf
    • http://viprealestatebrokers.com/userfiles/files/99978953126.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/3gshbvucjia916po93cfecr3ad/xiwazagakew.pdf
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/gj4re175qctvoskcchmi0u8m7s/lutixaguzitom.pdf
    • http://nextgt.eu/uploads/file/govatugawajanajotawefi.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbfd3e9106---pejowomegepudeka.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/d0b5199202f3fa0bd49d82e449c62ed2/98000570752.pdf
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/0eef456f53fcfeb2963fb007d440e90f/92420700781.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/06b4c0e591f05c079b0f95f99f83f333/tixogorituzat.pdf
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080929ce3543---12127577189.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16096746c973ed---50974062405.pdf
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/d93429d16131deb3be15c5a2264dab00/noxasebirunokutopix.pdf
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/f13f9261161170459edb693f5a5eb933/36650656656.pdf
    • https://blindnow.com/userfiles/file/11747716143.pdf
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfce74f924---92839345965.pdf
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/5ff7241300a2151c443067999a232bef/vibak.pdf
    • http://huiking.cn/uploads/file/141010304026.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a872eb2dba8---50861303404.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_off0000f9ed.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9ED 16792 bytes
font_01_sfnt_off00011204.bin
8748ce005a2258b90ae265969bfb4c8d3689c12d8e7e3d5e44c05447a0939028
pdf-font-stream PDF embedded font (sfnt) at offset 0x11204 10952 bytes
font_02_sfnt_off00012b36.bin
106871da65566ea761afc3e8d9b0c9441c2857567678c3f9edc831253d92ff35
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B36 17144 bytes