Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec8f76d1b78127b9…

MALICIOUS

PDF

87.2 KB Created: 2021-07-02 04:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bee43a1cac6ded79ac73f004a0d318c5 SHA-1: 72c792abe96ef558dba534f702cc0518ba3f120f SHA-256: ec8f76d1b78127b9655144e12c04b80877c061c9c2b631476c4293df8c177380
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the overall structure strongly indicate a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

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://synerhu.ru/uplcv?utm_term=powerpoint+designs+for+teachers
    • http://prestopc.it/upload/file/vuzigikafefagudesufag.pdf
    • http://shqinze.net/admin/upimg/file///57836215141.pdf
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a4baa20ce02---xefaxigikajinusa.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a03425256fa---lasudifapexi.pdf
    • https://klcmekatronik.com/ckfinder/userfiles/files/zoxesarogikejovumejadoj.pdf
    • http://firmykominkowe.pl/Obrazki/edytor/file/43207135159.pdf
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/849fa3b63b6233657bdde82a66c52397/tobotalaro.pdf
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/893d57f68ef9a387a1a76a0ee381dde8/31215051432.pdf
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/9d5b02768b003f65511febdd0a0fec43/vezegefasumeririzaduv.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/6de985d839eb95e487ce218da317554d/sudisizedimemenen.pdf
    • http://veterani-pushkino.ru/userfiles/files/24467565916.pdf
    • http://getem.eu/files/file/loguweditoburobifavokakub.pdf
    • http://broadgatecapital.com/userfiles/file/15561311006.pdf
    • https://atraba-holding.com/userfiles/file/88233510865.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a095add5b83---nolepukakuwitekadijanu.pdf
    • http://slphs66.com/clients/e/e6/e62fa13cff665df70d7481f632b33819/File/27543454427.pdf
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/a5eff8aae535c7fa4730c030e54417ec/zawibiromadevumupabef.pdf
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dad8e8cd1d---50888866165.pdf
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/csu6oubtjoq48fokided2ae5cv/wotonozomafutixagig.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe5f66e628---miwipalusinip.pdf
    • http://bioident.pl/photos_fck/file/gelavorutefekoz.pdf
    • https://kp-bs.ru/upload/files/depuruxetirived.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b79bc078c3---pesofi.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_off0000f1b1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B1 16792 bytes
font_01_sfnt_off000109c8.bin
2d9cba6a40c774729e19c42c2f2fc7f660d94d7785921f608f06e87884256e68
pdf-font-stream PDF embedded font (sfnt) at offset 0x109C8 10940 bytes
font_02_sfnt_off000122f4.bin
db8ba2119c25c24be7959f092a401bb74e18ee1c6b3ffca13f68090bac11bcce
pdf-font-stream PDF embedded font (sfnt) at offset 0x122F4 17152 bytes