Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bbbdd40d8e54075…

MALICIOUS

PDF

81.8 KB Created: 2021-06-21 10:54:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 44639bf5d3b5333dc0f07bf5714ec613 SHA-1: 46dd16f5610349188526228c312e876142b76cbf SHA-256: 9bbbdd40d8e540753b9fc7acd7bbac017d31fcde1642c49d028ee3749d977adf
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be junk data, offering no direct clues to the user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://mattress-leader.com/media/21570541341.pdf In PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bb4ecaa7775---tejawesab.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/2b5b6b830c7378e6863411db5e8f3593/xavoralenubopejovum.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/54829134467.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6aeaa33e1---8045870313.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/d70d5f50e5eaaa996063d383f3c79d3e/kijil.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/3a9d825b837e00cb6570442c9f484599/97654079847.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/l7dsanekd3t7i0ktkbgm5bgq8l/lunojilebidejutajef.pdfIn PDF document text
    • http://global-insurance-broker.de/downloads/dikesuwajigunimuwuw.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7cdc8816e---90603802764.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b231885c475---jamidoselifabokuraligadun.pdfIn PDF document text
    • https://carparts-fixture.com/file/file/nizizudixuxux.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609c978be0ba0---70780946798.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/69484580168.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071fcba043ff---majigatun.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/3008471784.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/71420704760.pdfIn PDF document text
    • http://parkhigh65.com/clients/4970/File/goxipavofunejupakem.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105131821In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=o+when+the+saints+go+marching+in+pianoPDF link annotation
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000100ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EC 5432 bytes
SHA-256: eaa95c2b0cf585c64c2d7e9576408478ff6687410161b2ae10dbbd5e4af9e183
font_01_sfnt_off00011353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11353 13536 bytes
SHA-256: 263c8ba834206c24c51cca5247be9616b74eb91e5cb664e55b9bc4b768d8e45c