Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b84443669b2ffac…

MALICIOUS

PDF

83.7 KB Created: 2021-09-23 11:56:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f44fd7a56b22318b4dbbe85b2c8ef604 SHA-1: d3d97afa6aa180ca358b9b35a58215f8fa05aaf0 SHA-256: 9b84443669b2fface60fe19fe31a279e618bac2c2cb830a6eea9e98e30a8e49e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of external URI heuristics and compromised CMS upload links confirms the malicious nature of the embedded links.

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://krisoc.ru/uplcv?utm_term=pokemon+ds+game+roms
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/3909e59e2177c0e3b35f21a3f2b5e090/jisurejodifereboki.pdf
    • https://holocaustresearch.pl/nowy/photo/file/71474926473.pdf
    • http://homespakistan.net/magzine/uploadfiles/file/63456438421.pdf
    • http://opusbiz.kr/data/editor/file/626571877612fda9648d4a.pdf
    • http://jiachuankeji.com/upload_fck/file/2021-9-14/20210914083644902385.pdf
    • http://komputerzagrosze.pl/userfiles/file/jabixepiki.pdf
    • http://5m-tti.com/uploads/image/files/xigebemirimamam.pdf
    • http://thewellmanteam.com/userfiles/files/xapawapifaworomijemow.pdf
    • http://nfrostov.ru/upload/files/supuguzasawejokudune.pdf
    • https://tlproduct.com/userfiles/file/gijatuxuxukemubes.pdf
    • http://stoka-saarlouis.de/userfiles/file/50771890119.pdf
    • http://e-hematologica.pl/users/file/xilonumizotidaniresiv.pdf
    • http://przychodnia-felinskiego.pl/uploads/editor/file/82000546443.pdf
    • https://svetplus.com/userfiles/files/fagewilixupinebopatafuni.pdf
    • https://www.vignolaweb.it/ckfinder/userfiles/files/wipurefidefaripupoxobe.pdf
    • http://elite-nails.pl/Upload/file/gubajejozarujovaxoxu.pdf
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/849dab9d3841e9e9cb8faafb863f742a/32493625698.pdf
    • https://akgoz.zemta.com/uploads/files/wedatiwu.pdf
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/7cebd2baa14a9df11c38ef8dd5db45b8/mawitetenozexetasiruwibuv.pdf
    • https://armature.ir/cache/fck_files/file/23615915661.pdf
    • http://www.ccengis.be/applications/ckeditor/addons/ckeditor/ckfinder/userfiles/files/gizulolada.pdf
    • http://elskup.pl/images/assets/file/66849169565.pdf
    • http://mousike.it/img_ins/files/rulamu.pdf
    • http://cofetariafraguta.ro/UserFiles/file/wibafizufogakab.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161337872ae7fa---nizomezubuxibifuzapesiler.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0d4.bin
27f8307dcf21fc97137f36aa03b01ec0534e06792f60fa1e5ae36fc0832dcf4b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D4 18600 bytes
font_01_sfnt_off000111a7.bin
81d9e7b9abf9f89e9abda1ad12fc9a67328a469ab7d899765a396696c97b925d
pdf-font-stream PDF embedded font (sfnt) at offset 0x111A7 10448 bytes
font_02_sfnt_off00012928.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12928 16792 bytes