Malicious PDF — malware analysis report

Static analysis result for SHA-256 b81e3337d16b9799…

MALICIOUS

PDF

85.1 KB Created: 2021-06-29 22:18:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 59d113a7e537f54a292bcbd27dab1af4 SHA-1: e7fc37880ca4eadbfa96985e7c035a03be3bc112 SHA-256: b81e3337d16b97995984e33e495b84c00de5e3f5dc79135cfc4630c4fe8bae28
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://whalesart.com/uploadfile/file///2021062501200968.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b58a8b1f409---13623838710.pdf
    • http://fitviewer.biz/files/file/fenutawojuxenujewosa.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160945cf1ceaa7---dapik.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b41f9b8af0f---disiridozovibixela.pdf
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6f25c3ccc---84071489511.pdf
    • http://anhbanglaw.com/userfiles/file/tekowemukedogetepewawov.pdf
    • https://gionggiacam.com/ckfinder/userfiles/files/venemanelek.pdf
    • http://matsonconstruction.net/userfiles/file/57183865392.pdf
    • http://ottotech.center/userfiles/file/80681489358.pdf
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/e84ea73d88c9f40b18088c599b50ed4d/tusiw.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160abf48a56309---newepo.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/22716958b4b1b4a4ebb96b2515363610/62128544891.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/l22nu9bi5uqt1opq8elgkmr6t1/20994443556.pdf
    • https://holocaustresearch.pl/nowy/photo/file/kumunojudalejimutazatu.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9d4126c4f---3248732733.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160afdac24b1c6---74521600799.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/cd4640415434cee15ab65e5fa449e924/faguvatiniwizerimomus.pdf
    • http://ersatzmonitor.de/userfiles/file/30915344649.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084244d56660---pakulalokamakumem.pdf
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/b28ee839e916938c9ed5acb7b9332112/lugosonufegelalusikasov.pdf
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/f3855d8fadcad501b8660e8cbe9bc7b2/bolavuzezufudipena.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6ce35de2be---41438318762.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=getting+to+st+pierre+and+miquelon
    • 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_off0000ed4f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED4F 16792 bytes
font_01_sfnt_off00010561.bin
76b64176671036d5427a33d985ceb148805c34b15579287d9f440dbbd6ddb68e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10561 15912 bytes
font_02_sfnt_off00012e2c.bin
98de93927a891f53ff17cf44b877f013c7e3de039c9cb74e9539386d30ae2145
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E2C 11020 bytes