Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c558a851cc1964e…

MALICIOUS

PDF

69.5 KB Created: 2021-09-25 23:03:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ef886f8184ca7d6f80a72296219f432f SHA-1: 36fb75299f594791c384473491224a83b7759e0b SHA-256: 9c558a851cc1964ed39881df170fbb835a655cd84b1968d6c979408d3145e49c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farm heuristics, indicating an attempt to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a common attack pattern for delivering malicious content.

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://krisoc.ru/uplcv?utm_term=voice+recorder+pro+apk
    • https://actsonics.com/uploads/files/202109220908277833.pdf
    • http://xn--lv0az70cxar.tw/uploads/files/202109090638045752.pdf
    • http://xn--2-140-swe8h.xn--p1ai/files/68860952698.pdf
    • http://sgyscom.com/upload_fck/file/2021-9-26/20210926030020135597.pdf
    • http://www.chp.pl/ckfinder/userfiles/files/wufavikilalesufumelazil.pdf
    • http://miroslaws.com/ckfinder/userfiles/files/vasebukelojamugakobite.pdf
    • https://fibaquitaine.fr/cebatrama/userfiles/files/pexenilobinamaboraso.pdf
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/nunofilulesinajes.pdf
    • http://dunajecbiala.pl/upload/File/ruloraxolemox.pdf
    • http://flapboxes.custompackageboxes.com/userfiles/files/sunijekibabefokokuzigodon.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614013447acef---21199517675.pdf
    • http://abwmarlboropike.com/uploads/files/wilizuxikafajoborade.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132a9ddad2ac---11861214993.pdf
    • http://euroear.eu/ckfinder/userfiles/files/ronuvotipowisurugoronowi.pdf
    • http://ticketsperiodico.com/galeria/files/wenisubibugidik.pdf
    • http://www.golfusa.be/userfiles/files/4137859482.pdf
    • http://craft-personal.de/userfiles/file/4994705939.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144db6403501---93507615057.pdf
    • http://daiichigroup.net/uploads/news_file/mubuxona.pdf
    • https://longhungphat.org/Images_upload/files/21396835557.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/161427bf120888---86724114271.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e69be8d1c6---gaxujudipixutavu.pdf
    • https://fruitssupplier.com/app/webroot/img/files/50463942482.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_off0000b056.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB056 16792 bytes
font_01_sfnt_off0000c868.bin
dc90e33dafa32bf3f811f6aec045db955833cc48b7d30f5fd8959b0d0e7a3113
pdf-font-stream PDF embedded font (sfnt) at offset 0xC868 16556 bytes
font_02_sfnt_off0000f23a.bin
605fa5c6eded7295a890b067bd1a436ee304e13fa3f9053b3a60597e18df1f20
pdf-font-stream PDF embedded font (sfnt) at offset 0xF23A 10152 bytes