Malicious PDF — malware analysis report

Static analysis result for SHA-256 851a356d96ad43cd…

MALICIOUS

PDF

75.4 KB Created: 2021-10-06 18:51:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: beabf0c3c1bfb99dcfe10dfb321ef5db SHA-1: 91a70e90fbf0add7b91cadb561856f0478bb9e04 SHA-256: 851a356d96ad43cdd2e875a39e120289bfd50ab508bd25549c4518a3b8403af2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to domains associated with compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution lure. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond the presence of embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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=baie+of+fundy PDF link annotation
    • https://maturana.cl/upload/file/zixezogedugug.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/25009f7f05c8df310495a67dd22e52fb/golesus.pdfIn PDF document text
    • http://355353.ru/userfiles/file/28065145197.pdfIn PDF document text
    • https://zlato-eu.cz/upload/files/45250552038.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/eb538329ac049e680d9c676b0c99e028/tojediretake.pdfIn PDF document text
    • https://kalendarz.probik.pl/fckeditor/userfiles/file/rozuvo.pdfIn PDF document text
    • http://incomingmakedonia.com/files/files/fugupo.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/telelawoje.pdfIn PDF document text
    • https://megalight.lv/uploads/files/fezesateroxavo.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/11897178766.pdfIn PDF document text
    • https://kultmotor.hu/images/files/6996936900.pdfIn PDF document text
    • https://shibbirs.com/media/files/wapuxikepozaxotes.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/27726340289.pdfIn PDF document text
    • http://studiolegalebisantis.it/userfiles/files/sijolobutoro.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/a0e7f8d9de473e29247f4f01481359e9/sesusozu.pdfIn PDF document text
    • https://stephan-kratt.de/data/reiterhof/userfiles/file/57904638408.pdfIn PDF document text
    • https://mamalight.net/business_school/uploads/file/dodimotovonat.pdfIn PDF document text
    • http://turar-mussin.com/userfiles/File/dasoseji.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/57510592544.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/89757156763.pdfIn PDF document text
    • http://ehomerealestate.org/images/file/fimojogekor.pdfIn PDF document text
    • https://nicklason.se/ckfinder/userfiles/files/96429387769.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/fixirifadekemajabaredeje.pdfIn PDF document text
    • http://humanlitech.com/files/files/43584842905.pdfIn 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://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_off0000c579.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC579 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD90 10204 bytes
SHA-256: 4e4fb1c1bb4d50c09d63792ea8db5f4bfb546a9e41753fc7b01e4650ce4181a6
font_02_sfnt_off0000f48b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF48B 16892 bytes
SHA-256: b641cf29fc29247aae3d74a85a6f7e210c6d0cf33059076a683aed38aa207f9a