Malicious PDF — malware analysis report

Static analysis result for SHA-256 437779d821a9c7ca…

MALICIOUS

PDF

80.5 KB Created: 2021-04-30 08:43:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: c0c3a306ac1470d003738d9168fd0ce2 SHA-1: 6adcbbf809105af5bcddb692302a715dcddf3353 SHA-256: 437779d821a9c7ca8c446ee0d20da2c5ae86dcd836992e4576fc53658951ee99
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160760153a8b43---48082674212.pdf In PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/smtnov367lm6c1e3uftegjskl4/murapuj.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/lariw.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/f06a525d39e068631941cf07ee7747a0/2634741107.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/bd2kked5psqkfbhbtql772l6mu/suwozopunetemafugemovotiz.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607cb9a3044b4---791569456.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/cc9e3aa45e0e71b6ed135280b80cfefc/14869365777.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/265c250013662c2bb6af781a1da050c1/72423017969.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/c95bb8da71a4c37b0526576e3a37aa3c/87648198659.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/08f6422ddae505ebc942c91d623b17e1/6910825599.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6d85b1fb5---91685719639.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072c563940f2---xuvepukotifaridav.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160750a2a6c721---85880640214.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=lagu+percaya+aku+chintya+gabriella+matikiriPDF 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0001093b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1093B 17824 bytes
SHA-256: f8f17554f412a33e4942bab141cdbe0c80fddc70387c30e565c8b2bb6ebc7fb0
font_00_sfnt_off0000d313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD313 5416 bytes
SHA-256: 3b3728220e345c7ddd5f87a5eb075d399d7ef38927e275610443ae91d6f8948f
font_01_sfnt_off0000e56a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE56A 10432 bytes
SHA-256: 6454ffb32fff24c6e529c9430697b4b296c435f12b3b540c935b6e6621824663
font_03_sfnt_off0001248a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248A 4212 bytes
SHA-256: eaf0af283c1f7944a4920ec993bf1a6587d00791cec1439fea051d48526215eb