Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a23b56a15cf858…

MALICIOUS

PDF

80.9 KB Created: 2021-09-12 22:14:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1e96309bc59c15fe38dde63538c5f7bf SHA-1: 8cba7288fdecf7ae2ab7d05214f823b89b731efc SHA-256: 16a23b56a15cf85872f4fd7d219ebc12c62f61c890984407a4781b01413e15ff
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://soechi.id/userfiles/file/vazagezakam.pdf In PDF document text
    • https://nada70.org/userfiles/file/fulenegumefesakosirepoda.pdfIn PDF document text
    • http://psn-monolit.ru/img_file/files/68446877966.pdfIn PDF document text
    • https://plasy.com/uploads/file/8241445769.pdfIn PDF document text
    • http://nuuts.mn/uploads/assets/jetapovabi.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/a70fcdc1eab025c486ae88216e533739/jawawo.pdfIn PDF document text
    • https://gkatsov.com/userfiles/file/jilaxeta.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/62692476652.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/1tfjm6s7qsc6gfjbak9lehdr46/55995258657.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/e183dbc12c1f18956470aa01a831f542/majirijojanaw.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210908030427.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/68235738794.pdfIn PDF document text
    • http://innotack.com/userfiles/files/37816718449.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/jilaveretikufugozufabuzo.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/79696494000.pdfIn PDF document text
    • http://csp.hu/editor_up/xoxotuvurakinubufim.pdfIn PDF document text
    • https://toocapen.com/files/lipamugakorijajipifogose.pdfIn PDF document text
    • https://oasis-travel.ro/files/xiwumuxudu.pdfIn PDF document text
    • http://coffee33.ru/archive/file/sapepagidusuwexu.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613deefc3f436---9072755919.pdfIn PDF document text
    • http://pazarziraat.com/userfiles/file/lazeverobopoxowoju.pdfIn PDF document text
    • http://simoncaulkin.com/images/wemujo.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/161360ec554bf1---3754803935.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613259bb47e93---57890503950.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+install+arm+translation+tool+in+genymotionPDF 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_off0000d6f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F8 17904 bytes
SHA-256: da65752782c93d4b1b110d2aaecc6e4224ee5e84df0f6bcec9dc822e9fdd591c
font_01_sfnt_off00010503.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10503 10644 bytes
SHA-256: 0e30d2f7771ebb50f0af604f50ddfe8738dc0ff91e0328839afebf5233c00ad5
font_02_sfnt_off00011d69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1