Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c8890c468d735c…

MALICIOUS

PDF

86.5 KB Created: 2021-06-29 19:29:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: f0c195f3e4578f76711907cd264ad516 SHA-1: 9f04fabb8eff7cbaed899fd04b83131b2b07d77d SHA-256: 31c8890c468d735c8e3b47d452dee8fdf0b4be4c44b6d0b1b312110139016194
176 Risk Score

Malware Insights

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

The PDF contains numerous embedded URIs that point to compromised WordPress sites, many of which are configured to host malicious files. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or to serve as a downloader for further stages. The document body is unreadable, but the heuristics and URLs clearly show a pattern of linking to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608297c858453---19729462742.pdf In PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe903b5773---94866444071.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c5479fc95---3136311451.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ea5262412---tirabisal.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/1620938232353.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/nixeziromirinifulasuxex.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd50895c8d5---51949599569.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/ea0b8b2764c58a30d19782d60b96448a/disuze.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4cf80bc917---tubutexug.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c91f6c89cdf---97478192101.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16076887def09e---popizuxipez.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16083c0f4ed477---36327999309.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/xozifolijikofisi.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/35848027580.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/03f3f3bf5c96fc68cd45f582ac2e38ae/76032768540.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609994f0722c3---xuwowitok.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a54fb9542---15512197271.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/a882cf6a13d2da5b4931c3ef0932ace7/riguxeliro.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/57757401191.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/061984f73c37dc0be126580b6599639e/gimuzilipe.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/4e71467029e9d0b0b3946de3f2b353b1/wunewinaviropemebaj.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/vqo15glblsfbgo51hhm9jm0bff/pemazugesofupajir.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e82d212e5b---45609636152.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a122b609696---61677004091.pdfPDF link annotation
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/39e8f692f3bfeb974591e7cf1dd45f26/zosut.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/80847087747.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=sore+roof+of+mouthPDF 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_off0000f4f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F4 10080 bytes
SHA-256: fef42b2da45f0975889550465af6ae29347f8be8aefa60161d4f7e218b9f517d
font_01_sfnt_off00010b74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B74 16092 bytes
SHA-256: 1049c8b0b564ff7e528d974c8ce0729e12d66b883e2b44559ebe59046a5fb9e3
font_02_sfnt_off000134e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1