Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa31c78eebfc53aa…

MALICIOUS

PDF

69.0 KB Created: 2021-09-27 14:31:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b068a2443f875231c3f841a20764be64 SHA-1: a37a5b04190dad3b65c29067120999c1eb03ea05 SHA-256: aa31c78eebfc53aac1d37c42cb5dc450a025083446db6185588eaadb954eb387
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs and is flagged as a link farm, with several pointing to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://drafthe.ru/uplcv?utm_term=linux+for+arm+processor PDF link annotation
    • http://wintec-samu.hu/uploads/files/tesixisawunojoteribugipu.pdfIn PDF document text
    • http://cabini.it/userfiles/files/14271364401.pdfIn PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/44043583475.pdfIn PDF document text
    • https://oldgradeducation.com/ckfinder/userfiles/files/47893700286.pdfIn PDF document text
    • https://tunhuaduytan.com/upload/userfiles/files/jaruzetexikoximijofipefe.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/76892286668.pdfIn PDF document text
    • http://bannhuaduong.net/upload/files/92579714346.pdfIn PDF document text
    • https://alident.centralcms.cloud/galeria/files/tugudevivexerupe.pdfIn PDF document text
    • http://robedecreateur.com/img/files/rakozuvofo.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/73571282599.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149c70e529cb---kopisalunurasilomaxa.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614542ac9fae4---49356897218.pdfIn PDF document text
    • http://bannhuaduong.net/upload/files/tuweziwuwisunugumog.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/gazanoreremewirotarul.pdfIn PDF document text
    • https://reklama71.ru/upload_picture/63726580982.pdfIn PDF document text
    • http://eventechsite.com/files/files/29480569395.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/cd721c6146b6a5ecb652ec460f3bdb65/46898353284.pdfIn PDF document text
    • http://style4.allwebeasy.com/userfiles/files/sonuwesivimavajex.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16138304bb05ea---57308811080.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/kenabewi.pdfIn PDF document text
    • http://schule.havonix.com/ckfinder/userfiles/files/71769857281.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614730516820f---10421685924.pdfIn PDF document text
    • http://lejonhund.com/upload/ponin.pdfIn PDF document text
    • https://fertilizerproductionprocess.com/d/files/50272395267.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/josusejasenovepekedoziz.pdfIn PDF document text
    • 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_off0000afe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFE0 10656 bytes
SHA-256: 3771e39c7167a80517780b0ab5c7c7ddf503bb2e4711acdf9d3b85b3e96b23e2
font_01_sfnt_off0000c840.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC840 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE052 15232 bytes
SHA-256: 54cb300fc6cc470ee07543a92b9ed050657e98b1adf02ecb8a7443e0c39880da