Malicious PDF — malware analysis report

Static analysis result for SHA-256 531387e962fef832…

MALICIOUS

PDF

88.0 KB Created: 2021-09-16 20:30:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2566620cf042492d78dcdcf022ced601 SHA-1: 09a0dcf93b696cae797958342de3b18f34dffaf3 SHA-256: 531387e962fef832198948bd1ce1afe1d1b6f4760053e06644e208a6dc8d3f5d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload directories, suggesting it's part of a link farm designed to redirect users to potentially malicious content. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this, indicating a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://smidgel.ru/uplcv?utm_term=gta+5+apk+without+human+verification
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613304a6b2625---nuzosopijum.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16134a4edb984f---64313357910.pdf
    • http://giasuthienphuc.com/Images_upload/files/jipobujalo.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422a0ce9158---70027469734.pdf
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/sunetasezibub.pdf
    • https://airxps.com/userfiles/files/muduxufojal.pdf
    • http://studiotecnicoforace.eu/userfiles/files/zowefomexerobe.pdf
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a673503691---zujanix.pdf
    • https://www.amata.org.uk/ckfinder/userfiles/files/36282007815.pdf
    • https://ruedi-leuthold.com/userfiles/files/65577488117.pdf
    • http://kesifveotesi.com/files/46382132717.pdf
    • http://lavalnerina.com/userfiles/file/38248886498.pdf
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/pgcsoe24at4le5n5ktbtg8erus/danudemewuxizaw.pdf
    • https://btsis.com/upload/ckfinder/files/16128856344.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/008e6962fc1718c993564397f94954f4/3659395588.pdf
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/74740277062.pdf
    • http://www.findvoters.com/userfiles/file/27640794124.pdf
    • https://tims.ro/ckfinder/userfiles/files/5316533221.pdf
    • http://akcjonariusz.com/UserFiles/file/50186216433.pdf
    • https://betalinktech.com/blmedia/file/wurosugavu.pdf
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/549c5f9c5a80e983d16abac25775ea61/82634158499.pdf
    • http://jinanxintiandi.com/userfiles/files/makemujadepoborozuxuze.pdf
    • http://labsshop.com/d/files/gakuneti.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/tasn7fplr8bg7g9kqhnsr6ni25/58111444384.pdf
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/87245475874.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_off0000f305.bin
d54e1522d3429f5586bec9679dedac9c984f4511a36331baa92c26106c6a48a4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF305 17780 bytes
font_01_sfnt_off000120e1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x120E1 16792 bytes
font_02_sfnt_off000138f8.bin
a51fc8a8f4b8812b7642fe0a909d2c86d162f13352092b9d2dbce4b9b0d49460
pdf-font-stream PDF embedded font (sfnt) at offset 0x138F8 11048 bytes