Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6d794fcd0c57045…

MALICIOUS

PDF

80.7 KB Created: 2021-09-16 17:45:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 31b0ad57146a9fa9e350bfb5c55a388d SHA-1: f32b66358253de6ab6cf792cb739076f9c06ebff SHA-256: a6d794fcd0c57045d80501712aae4b6cff967b2a5480bad78bd482425f3f5810
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the PDF structure itself is leveraged for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://synerhu.ru/uplcv?utm_term=decompile+apk+to+source+code PDF link annotation
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac2f0f379a---96900283124.pdfIn PDF document text
    • http://davidhammerstein.org/ckfinder/userfiles/files/47342005519.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/fumunamiwusa.pdfIn PDF document text
    • http://roseeskin.com/userfiles/file/20210907145956.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16132e688a50bc---nitogitow.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/liradefogibaxe.pdfIn PDF document text
    • http://familie-schiecke.de/images/file/16278496939.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/70777381616.pdfIn PDF document text
    • https://3rproject.eu/ckfinder/userfiles/files/65698554021.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/7su4mrnuvknfcql8kugu2j6ac1/49761078338.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/li19k66jjoej97ih98r8okpsaf/malewokujusutos.pdfIn PDF document text
    • https://watosaphotography.com/app/webroot/userfiles/files/20210907_005129.pdfIn PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/galilidajumite.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/56090670924.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f98c578221---davepipoda.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/dizikunos.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614137a79661c---lusaneripisefelorofopeva.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/3d6fe9d29e25fe3f7bf45bcde78e7101/dufep.pdfIn PDF document text
    • https://tes-sys.com/uploads/ckfinder/files/20210904/16307531046792.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_off0000d35a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD35A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB6C 18592 bytes
SHA-256: 374158779d038c4b1f4222ac8e3a6ea9e0f163928c5abb22a66e8b3f238ddb07
font_02_sfnt_off00011c85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C85 10764 bytes
SHA-256: 137aedda49e149ef613eaca8e551c89c941647f024593b8a477c3d33889edabf