Malicious PDF — malware analysis report

Static analysis result for SHA-256 1535879303a8adaa…

MALICIOUS

PDF

71.5 KB Created: 2021-06-18 13:35:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 5f0adab4867bf308e7f84037cf7fde73 SHA-1: b25ea37209cdadfe6134aa040c342f2c96bcc58a SHA-256: 1535879303a8adaa747edf362bc73a253ad2c251b562be54f32d15f16e947007
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. These sites, in turn, host further PDF files, suggesting a multi-stage lure or download mechanism. The embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/d25ffbe91933b07dccadf285403419a7/jawokitaloraz.pdf In PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160837d73ee487---84971382734.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607584056e166---lebopenepewutizovisit.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/46087407005.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/b34d9336adf2606d8d1059ecaf7ddb12/84683483496.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/e65c09918a4df872cbc8d34b8d4eb972/sumezoxokama.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/b114f4de051c02635477d114d3241f01/pininejutajisatolosedanod.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/mos48vbiannq3a91ei6vq25fdg/rumanesafalunugeduz.pdfIn PDF document text
    • http://wannawwannie.pl/userfiles/file/7352979757.pdfIn PDF document text
    • https://mclarenquartz.in/ci/userfiles/files/37490611149.pdfIn PDF document text
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/4ef22490e52897cc4944e84b4ed75a83/16799217557.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160867facaf9f9---vanube.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/e05f300191b028462ef224b14f1d8aa5/41376326615.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/ccf7077f99d2f26cc516e7879afe7c71/vezod.pdfIn PDF document text
    • https://benjamindreyer.com/wp-content/plugins/super-forms/uploads/php/files/34a7da65e90f73fbe231aecb97bef497/22049458359.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/mawiwodamobolivomipekag.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160835eee18cc0---57744232853.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=technology+used+in+architecturePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d96e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96E 5252 bytes
SHA-256: 00e5931d960fe61eed81f0d040baa74ca2dc5b2162d95e8b6d18325176bd5070
font_01_sfnt_off0000eb4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 11192 bytes
SHA-256: 3e9c61430a99c8b338f920dab60e23b43cd7c88c1d543059f9ace3507987679d