Malicious PDF — malware analysis report

Static analysis result for SHA-256 277bddffd491d4ea…

MALICIOUS

PDF

65.1 KB Created: 2021-06-10 21:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: c20714af9e2f9a68a67d9a8121334731 SHA-1: ec7dcb85dcd242ff8acb918cd1d9d990a4521329 SHA-256: 277bddffd491d4ea5e1d06f7a3628ef83f706602b29d9784a5798f9819e8fab3
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous links to external websites, many hosted on compromised CMS uploads, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest the PDF's primary function is to facilitate initial access via spearphishing, leading users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=factors+and+divisibility+rules PDF link annotation
    • http://pivotal-technologies.com/userfiles/file/94636590502.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160908d7aec1be---faxazinebuse.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bf292078f1b---kowomi.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a25fd94edde---varogujizirukuki.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b43cd28c266---duxezajewapasomodubudef.pdfIn PDF document text
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/fcf4406c27dc00f30d036b65f6bdd9ff/90085620192.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609064e3e0425---damazez.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/72a1a71c4c420cf830c02f23f327cdc7/dumadarazinisi.pdfIn PDF document text
    • http://prestopc.it/upload/file/70019997675.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/89d3f6b9ec9a73065979d0047cd21e3f/79489092478.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609cacdf1563e---79041356275.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608471da3b374---ponigusibepejasuj.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/53786088385.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/72qsickdh04qn00p193rgs9tig/pewinomenotajarawaroseg.pdfIn PDF document text
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/22b533fd02b07cdd901562d486494091/musiponusamapokusonobiwim.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609bdd906f241---22874259992.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b1e0ae1df---48209551096.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_off0000c4a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4A5 5188 bytes
SHA-256: b85d135eeec0856bdb1172154380a0f83b7e79d7f0599b88868963b75862a160
font_01_sfnt_off0000d662.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD662 9728 bytes
SHA-256: 0afeca8e5f5851a5178643166c273a020d62b83fd91209b15d4f284fe86f0993