Malicious PDF — malware analysis report

Static analysis result for SHA-256 51acf06769f40965…

MALICIOUS

PDF

84.2 KB Created: 2021-09-04 21:53:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: fe6b3dd4527a08e4a3ff20462d090754 SHA-1: 2017096e20bf09ea016d992b5b58a99a1b76ca36 SHA-256: 51acf06769f40965b916aca072c360a7ffbeb159cdb2e78d3bc3a7ce9d9e26eb
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. It also features a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites, suggesting an attempt to obscure the final destination or distribute payloads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://geredekombiservisi.com/userfiles/file/xakazefizineworer.pdf In PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/r9vdvb333701b87r66saapdsgf/51075172509.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/e1bka9ikanierq6buhf58skr4i/12056821257.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee92ce54a29---41532494088.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fe550f1e6e97630c7bf7087e43aa8771/fuxosararedopo.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/28684723629.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160f50a1d97c8f---31450234508.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/59259644394.pdfIn PDF document text
    • https://ckmandarin.com/uploads/10843497972.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/44647717882.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/merusasemowu.pdfIn PDF document text
    • https://lionkingbali.com/uploads/file/65695302996.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3415e8978---24377015115.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/229d9bdbbac327d2a0e9beb14dc32ef5/barenoj.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c33fa6b21a9---71226496298.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/74990797806.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/9fb816bfa15003b93640f352af530a2b/22566330168.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/751152e4191c9ec9382f35987f28322d/89838627642.pdfIn PDF document text
    • http://hhsbluebirds1967.com/clients/b/b5/b592d679e9980e62d9d56be1bfb8b6b6/File/waxixazeno.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/3121f692349b1b337ae313431b78abbe/numunepage.pdfIn PDF document text
    • http://scuderia512.com/js/upload/files/jafukekebaje.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/nufube.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/74787017944.pdfIn PDF document text
    • http://ghhs1968.com/clients/5/57/5762190d0a265df614d1f295a7060a42/File/favufixolesixuduwo.pdfIn PDF document text
    • https://bibonatura.hu/ckfinder/userfiles/files/91737385166.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210901220056.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=principios+eticos+medicos+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_off0000e39e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE39E 10572 bytes
SHA-256: 714e54b738664297158c95fb18f4f7d100a45c56c6c09dba70dd278b6d0202b3
font_01_sfnt_off0000fbad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAD 18536 bytes
SHA-256: 4c3c3aeca9e095789351b60cbc29b659a8bb455b5ee511983e0206c8657b155e
font_02_sfnt_off00012ae2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1