Malicious PDF — malware analysis report

Static analysis result for SHA-256 b481cc0af694f8c9…

MALICIOUS

PDF

75.4 KB Created: 2021-06-14 10:28:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 25601b4c2e6a8c9c629a46bb5d63b8df SHA-1: 74d9b3f72b655a660ea8bc25b39e5d3897762f47 SHA-256: b481cc0af694f8c90c4328fa14d68afcb6cb711c2653b35a8d91a09d4cc159da
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple embedded URLs pointing to various websites, many of which appear to be compromised WordPress installations used for hosting malicious PDFs. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body, though heavily obfuscated, contains a search query that could be used as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://irlanc.ru/uplcv?utm_term=who+is+the+richest+person+in+the+world+2007 PDF link annotation
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/9fcf552624687471bc0295ad4957204c/zufajifodizaxuka.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/xudum.pdfIn PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/jolorineb.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c5a73c653c0---zapuzapepasidilu.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/moluwokud.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075b648aecfa---rarutarifevijivopemaxote.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/8caa93e5a4e1c97822e36e906cdb7d43/15266149626.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/19018ae8cb9f27654571a3e1eb172d16/32242521856.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2d3d07129---solurawibo.pdfIn PDF document text
    • https://ckmandarin.com/uploads/78784834493.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e3f619540e---muzemedotusowexekosipe.pdfIn PDF document text
    • https://mobilieroccasion.fr/uploads/file/ralawizofet.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/0pvhsc1fukfer8v67ipt7v36pr/mopugezakukivalefopum.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/jaxijobilixonile.pdfIn PDF document text
    • http://ahs1968.com/clients/d/dc/dcea35c349c70fb55dca458fc6558ff6/File/resixiberizozep.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/9a404a36170b2fe5cf747b3f5eefd722/81395568972.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E3 5408 bytes
SHA-256: b6fa4210dcfb42ed89212c38d8fe46e876c43d6ea7ee9c562c1b3b8e18ae9103
font_01_sfnt_off0000fb70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB70 10924 bytes
SHA-256: 7a79e472192771b07327adaee48c08b85e703e221ed177f70d84fd500b57bc59