Malicious PDF — malware analysis report

Static analysis result for SHA-256 829d157f0e3c7442…

MALICIOUS

PDF

76.5 KB Created: 2021-08-15 01:54:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f5ca7cb244a26a92b4c7bdcf9700c1fb SHA-1: 503a602c08f9b907842e66f738b513ce16a26130 SHA-256: 829d157f0e3c7442ad19011b82e283e9baa6a16d61bbe40f7fcbff854b3fd7cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users. ClamAV and ML classifiers identified this PDF as malicious, likely a phishing or malware distribution lure. The presence of multiple external URIs and compromised CMS upload links suggests an attempt to host malicious content or phish credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081efa639507---jetotiba.pdf In PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/gdrpagpfpqjq6gidpmf7j6rktm/25486606883.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/98556788464.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog//file/wufukodidolu.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/nibofapenafoxonakiduwopor.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc83473f02---68515206897.pdfIn PDF document text
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c17806ecc55---zegapajowufavumeburobija.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1608c3e9933edf---31181177087.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/47480960606.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160adbc9e94c7e---birirowej.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca122d80fb---kugodib.pdfIn PDF document text
    • http://clarasonic.com/upload/file/sidowonobusidix.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/misatiradulusol.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c41f3160e---nasukesesadujabekelemef.pdfIn PDF document text
    • http://rhondachem.com/d/files/8170869559.pdfIn PDF document text
    • https://tavio.ru/files/file/vazalolex.pdfIn PDF document text
    • http://pc75.net/upfiles/file/1627466818.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b26fe87d6c0---6884417188.pdfIn PDF document text
    • http://myslizdrave.com/soubory/zorunefot.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607276eeebc77---metoxevetadosurirox.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160dfde9d16b91---julatezir.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/ximukegogivimagabini.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607d543f385b3---66643147513.pdfIn PDF document text
    • https://rhodium.vn/uploads/news_file/saverasibogawovataxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=fisher+and+paykel+dishdrawer+error+code+u4PDF link annotation
    • 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_off0000c86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC86C 10960 bytes
SHA-256: acd84ff9e12d77ec0a4681e6d211f07187ea07c78ce42a3fee9a1ab13fe08de2
font_01_sfnt_off0000e1d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E8 16368 bytes
SHA-256: 577df8adadea55df3b1bddd91d6fd6db2fa85066709c7514d5f0458a5d1c8a1e