Malicious PDF — malware analysis report

Static analysis result for SHA-256 91071bf55c8660d1…

MALICIOUS

PDF

71.6 KB Created: 2021-09-04 18:11:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1f6e7bfa8ddccb392b8efb7317c8ddc4 SHA-1: 6184a23ede4290b2055aac0a5ec8f1c5778e85c5 SHA-256: 91071bf55c8660d12908c4f0dfe1a6fdf5a680d445ae48a9b14af08fc34d149f
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs pointing to compromised CMS upload directories. These links likely serve as lures for phishing or to distribute further malicious content. The presence of multiple compromised host URLs suggests a broad distribution effort.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/7c2cef0044550291b23243bc7e11746f/18874455216.pdf In PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1611f697524ea8---wavameduzelu.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/e8df92803068606ff06164720805071b/wikag.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/bejadutobuxune.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160795080a120b---64311983337.pdfIn PDF document text
    • https://mimpishio1bet.net/contents//files/sokurave.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/d08f5f8bf7789b8928592c17b10a1c7a/6681080369.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/58494830112.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/47866672459.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/9d6142d68b35f110c3489c4e3d9d97c1/birixemenebise.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/xupogigateverupoxonefaw.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/a80r8011lch2r6qrs1kontg8qh/87360253533.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/632d5b5pr5dpgvs96e34qjo5e4/sexapi.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/gafof.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd3f30abcf---mizarakidawolanupa.pdfIn PDF document text
    • http://congtyvima.com/images/Download/25969282477.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b6397b456c3---49145557142.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/0ddpelk8rlacuhibhfpt5erlfh/70083849592.pdfIn PDF document text
    • https://wickedcheesy.com/images/file/91098629613.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/porex.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608a403778b5f---76003278007.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/t0i0n2pdq4i1h5u0spmhno6llk/99194778515.pdfIn PDF document text
    • http://ligneus.hu/upload/file/68326721871.pdfIn PDF document text
    • http://cravaluos.com/ckfinder/userfiles/files/bomadokumaz.pdfIn PDF document text
    • http://snft.ro/media/file/49011708551.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=junior+panchayat+secretary+material+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://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_off0000b765.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB765 15460 bytes
SHA-256: dbdcd398d07e34bb1d61302de1a178bf62d9a7af100beac0bf365fa446f189e5
font_01_sfnt_off0000debd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBD 11092 bytes
SHA-256: f2455ca3d4099af31610e54d916d147cec7b7342d9e00568311986ff9944984b
font_02_sfnt_off0000f873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF873 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1