Malicious PDF — malware analysis report

Static analysis result for SHA-256 603197f1c3b656d1…

MALICIOUS

PDF

84.8 KB Created: 2021-09-16 15:47:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a9349c8fbe9c680ecc5df6889f8fa457 SHA-1: ff6b37dd9a1cbe622b26833bc6cd6e35372ef0bc SHA-256: 603197f1c3b656d180d559addeb046d35fad46e3bd04d4f67ecc8d13c7b36358
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or SEO manipulation scheme. The document body was unreadable, but the presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://sodigital.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613f81f612cca---43944882881.pdf In PDF document text
    • https://hyundainhapkhau.vn/upload/files/60985373389.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/037239c6ad10b7dbb817b8fe75da3632/85687116827.pdfIn PDF document text
    • http://thepducphat.com/upload/files/sozujujorederiwakudar.pdfIn PDF document text
    • http://coeb.eu/userfiles/files/zonibi.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce6b10b121---dimalimibaderidi.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/87449040955.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/pelut.pdfIn PDF document text
    • http://immobiliareborghi.com/userfiles/files/85613502008.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/vizopubejuvubinured.pdfIn PDF document text
    • http://psychologadamczak.pl/userfiles/file/87912701223.pdfIn PDF document text
    • https://hoongnau.com/upload/files/nemuludin.pdfIn PDF document text
    • https://ancoraeducacion.com/images/94891595252.pdfIn PDF document text
    • http://jfe.hk/userfiles/24662526423.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/54143125714.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/62616480856.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/95686366731.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/wumilujebuduwarewup.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff3f94fb46---454925145.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee2fbc5b73---zumun.pdfIn PDF document text
    • https://giolog.biz/images/bulk_images/files/julonosebofanewosidobu.pdfIn PDF document text
    • http://tpfish.com.taipei/archive/upload/files/76612487739.pdfIn PDF document text
    • http://dglytbt.com/upfolder/e/files/20210902024225.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/koxoni.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/0ddd31c130ff8a1a13878527220fa7ad/96684019857.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=free+keyword+listPDF 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_off0000e91f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91F 17800 bytes
SHA-256: a9d7a84e94be4cf38d05164ca4b3f251d1e1bf594abf56ca77876f07f86bed36
font_01_sfnt_off000116f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116F4 10244 bytes
SHA-256: afadd4aa57e2fe90e7de086543c4b65ec804c227a5e51f48d05985eb324da903
font_02_sfnt_off00012e27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1