Malicious PDF — malware analysis report

Static analysis result for SHA-256 33db7ea997ed597e…

MALICIOUS

PDF

88.1 KB Created: 2021-09-21 15:34:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2165777f161dfec0b844f5a7e2ffa61e SHA-1: 2aaf37c3008362863567e87d6b8cc0c95c1f8165 SHA-256: 33db7ea997ed597e9138c8d7277d429b2481417b4f88a7cd1a25731676f08b15
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics and an ML classifier as malicious. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection 'Pdf.Phishing.Trojan' further supports a phishing or trojan distribution intent. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a phishing lure or a downloader for a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://crysiq.ru/uplcv?utm_term=android+emulator+no+internet+mac PDF link annotation
    • https://riondene.ch/img/uploads/file/foseturefowasiruzarekose.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/mr9gjhb6k93bqoh85as7vvs0c1/49413958454.pdfIn PDF document text
    • https://jajugroup.com/ckfinder/userfiles/files/72672554330.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/bc50cf69d869871e64b6250bbc092841/lelefavitojofafepodot.pdfIn PDF document text
    • http://airelimpio.mx/img/editor/file/14109966222.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/natemopab.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/dedopidovax.pdfIn PDF document text
    • http://rrarental.org/upload/file/nogavanesukazofog.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613e40cf9513f---79182888859.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/tizobazuvi.pdfIn PDF document text
    • https://tekstilkentrehber.com/upload/ckfinder/files/53082501388.pdfIn PDF document text
    • http://ekstelekom.com/userfiles/file/23091065500.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/32335446415.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/zujeli.pdfIn PDF document text
    • https://digireg.ch/upload/nokibopozirevasopew.pdfIn PDF document text
    • http://2safe4u.cz/UserFiles/File/dozedivu.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/sopoxesobol.pdfIn PDF document text
    • http://ogcdc.org/uploads/ck_upload/files/58637174680.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/zabetajufoboniti.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/74211441708.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_off0000edc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC6 20512 bytes
SHA-256: e854021bd67b89800d84084eb038538bee34658369782a5e1ace2bdd94039afd
font_01_sfnt_off00012326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12326 10444 bytes
SHA-256: da034e8d9851c8eb796698366fde17c11b0e014cc62892741b6a8c21f60fc8e2
font_02_sfnt_off00013ad3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1