Malicious PDF — malware analysis report

Static analysis result for SHA-256 d55bf35e14eed740…

MALICIOUS

PDF

94.8 KB Created: 2021-06-27 18:41:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: cc6ea2b45795b7f5389077a4ad7dab7d SHA-1: 0ec4cb15e7cdad5c724cd82a021ddb587d020721 SHA-256: d55bf35e14eed74091e5911b33deeed362003aa8d1fea788f7f2712f82b45770
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing trojan. It contains a link farm pointing to numerous URLs hosted on compromised WordPress sites, which are likely used to distribute further malicious content or conduct phishing attacks. No scripts were extracted, and the document body was unreadable, but the presence of numerous suspicious URLs strongly indicates malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9806

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://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160b6b60822cda---biwevogije.pdf In PDF document text
    • http://wawa757.com/uploads/files/melegivupa.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8924df4226---1638917812.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afdd92e8462---golapabaj.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc35965a89b---1580573959.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7aa9e7e1b---84854094629.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160a3693407f7c---vomufuxuxumagojitaw.pdfIn PDF document text
    • http://brandnewgoods.net/userfiles/file/85839828149.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/48189164660.pdfIn PDF document text
    • http://artospace.com/pics/file/latogopazenulo.pdfIn PDF document text
    • http://asckhn.com/acskhn/userfiles/file/78636972604.pdfIn PDF document text
    • http://fedoro.ru/upload/file/fatom.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/c1dab525f5ab4b99667205c1c08aa006/rilezeke.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/d1ce08139ff6f9b2ace371f7fb7e2399/83965803084.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/50236316146.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/g8gbcr2mbuth2a4scuh4afkhf6/15856159144.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/tanakeligevanixolovujex.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160815eaa5593c---54860097843.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16099e48708f5e---60366427315.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160986b368b8c2---nelasubumafavite.pdfIn PDF document text
    • http://avision-italia.com/userfiles/files/fovopitufedoja.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160811b4f8cf00---41509283305.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/73hedtb0o0um78ch09ackfuk9f/11821568894.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/14375655720.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/d3de26ad4454fdded86ecb39e41bc2cb/98855106781.pdfIn PDF document text
    • http://traktorpulling.de/ablage/userfiles/files/namizorawetiwanukidatulol.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1fc4d491a---23865067693.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+aim+a+compound+bow+without+sightsPDF 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_off000110b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110B6 11000 bytes
SHA-256: 4faa325b9479996f7e43dd5278b36629bb75d9d902b02c0ea5f2240fbec81dfa
font_01_sfnt_off000129a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129A6 16664 bytes
SHA-256: bade38ce6cfd752eed086196af12666b829a0653432dcc63e795f4876754e3f2
font_02_sfnt_off00015521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15521 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1