Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef906ad3ae4a7062…

MALICIOUS

PDF

87.9 KB Created: 2021-07-20 01:42:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b9073c326931d929623753c0e1b1743d SHA-1: e601b536a6f12d0425e20d774166eeb908e2f1c0 SHA-256: ef906ad3ae4a7062e18bcaebe18dd5bd4eee0c18662f6fa20ccaa4dca0541016
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. Several heuristics indicate the presence of link farms pointing to compromised WordPress upload storage and disposable hosting, suggesting an attempt to distribute malicious files or redirect users to phishing sites. The ClamAV detection and ML classifier further support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d011ceb0100---86738311194.pdf In PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/7e4pv5at2953heeq4vgptso5un/58502514277.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/vajunobigodigutogavul.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/jagimudugesuwozu.pdfIn PDF document text
    • http://smclassof57.org/clients/34860/File/takirivunemenevezij.pdfIn PDF document text
    • http://peach2560.xyz/js/ckfinder/userfiles/files/2826979648.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/mafuvigefemabutatitaf.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/4917249210.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bf116254d---zigoparujux.pdfIn PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160961a22cbf05---48864783319.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16087135da72d9---88479392913.pdfIn PDF document text
    • http://gloucesterclassof81.com/clients/23558/File/jimodumabogak.pdfIn PDF document text
    • https://wipaphun.com/UserFiles/File/zepazibajeposukuj.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160dc6ddbf1a19---88221023726.pdfIn PDF document text
    • http://extracam.es/app/webroot/arxius/file/38383398510.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/d8e1d4c71a2e2d6a0612fc5ef915262a/85594183464.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/29c0a1762acfc0409580534ed14843b1/wurujefo.pdfIn PDF document text
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/3331288b2e89c34a444a9d53a5b6feba/selefodukaxeselim.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/sujupixojukaduti.pdfIn PDF document text
    • http://rydelko.pl/userfiles/file/54634712512.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/251d3fc90c36a72e7676bfbdbc9faef1/wefutumojurijulovafivise.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/aac9464e532fba4b301b22f4af3f79fd/83296699968.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/2ac4faeaa8f0fe153646e1d1a4d8c860/70078009569.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/6q58kbqc5374rtgpcdt43m5lp6/wejutojadabukuwato.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160cd381d14e23---906587802.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=fatal+attraction+nia+longPDF 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_off0000f642.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF642 17484 bytes
SHA-256: a9afae26c17d6c4f03df9bbf271935b9c4ef04ec8de3e38e134913861a0b636b
font_01_sfnt_off000123e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123E0 10084 bytes
SHA-256: 7efd3ab42f15ecd1a555cfb8ec7a1c5f81b5526cd990327a6839890b165f967d
font_02_sfnt_off00013a6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1