Malicious PDF — malware analysis report

Static analysis result for SHA-256 67c9d361313184f4…

MALICIOUS

PDF

79.5 KB Created: 2021-06-18 21:51:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: bd21e973a0d6d25d330e030334a2c90d SHA-1: 187d566fde209f871f060c39afc8b467fb0e7450 SHA-256: 67c9d361313184f4c2a0e99f4f5bace45675fc043adf9a9bd162b11044414653
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to compromised WordPress upload directories and disposable hosting, suggesting it's part of a link farm or phishing campaign. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing lure, potentially disguised as an 'Aetna medicare prior authorization form'. The presence of embedded URLs and the nature of the heuristics suggest it may attempt to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/a0243d7a5294cb099340e21d0c01e717/gukewodexijum.pdf In PDF document text
    • https://cordovajewelry.com/images/file/faliselonapabo.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/baad59c1cc53a9e16deba44776b949e7/xazuropozijemubusagit.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a01d514b0d5---65927489399.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33ee39797b---89157441288.pdfIn PDF document text
    • http://menafundinfo.com/userfiles/file/fenuz.pdfIn PDF document text
    • https://sanidom.pl/img/file/41754197399.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd24e561dd---jasedofozozewetenuxut.pdfIn PDF document text
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/e21bab4be675fd6c673ac1b95473dd9c/vezenosojemivabotuwimesu.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/dc42c37dfa819de9e9314ea0e8355eb3/barupi.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607579078d005---dofabuni.pdfIn PDF document text
    • https://condominiobrisasdelnorte.com/userfiles/file/76971244407.pdfIn PDF document text
    • https://majubesar.info/contents//files/79421310900.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/wekaguxokudewapamil.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/susujevekodomuramabudig.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eff81b3043---fofuzatituz.pdfIn 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/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=aetna+medicare+prior+authorization+form+pdfPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F6 5224 bytes
SHA-256: 5a316b0dacc4bb2d61916b93acb4ffeb5ae3b5d1586aa5096b126f30698701cd
font_01_sfnt_off0001099f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099F 11616 bytes
SHA-256: 26d4b9191dbc10ce28b467cf73f8036e1c588d4937e283202aeb25eb4ce2b849