Malicious PDF — malware analysis report

Static analysis result for SHA-256 337b50acb5d1f0ef…

MALICIOUS

PDF

70.0 KB Created: 2021-06-18 12:06:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 74dd04025b4357c2610d818f0f32a585 SHA-1: 6239a131602f13888723b14374e88b9591bab1d3 SHA-256: 337b50acb5d1f0efd0050cc25f01ca9c7212ab175a927754637fd6a0974a7786
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF document is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It leverages a link farm hosted on compromised CMS uploads, masquerading as a free PDF reader for Windows XP to entice downloads. The presence of embedded URLs and the nature of the heuristics suggest an attempt to deliver a second-stage payload, likely through exploitation of PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b7d1d6f2641---52359839500.pdf In PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608ed1be99d74---21156810857.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/3472ac1a0638fa5a4d8b462e9139a630/38499754292.pdfIn PDF document text
    • https://viboot.com/ckfinder/userfiles/files/modesukenumatiji.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0d2b9a62f2dee01e04fc220cedfb4443/tarobuduwesajinudepatado.pdfIn PDF document text
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/dukivolodegamumusovug.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/8c2a1060c6770097e2de727fd55fe862/93835824318.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/68613809599.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a8cb8c2aa32---gaxededi.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/4rc4pjacei4fi98n2d5o2oldk5/zizufitukawaje.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccf45c3cd6---5266467821.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/5bc48a3e553f60f35e95c5fcb6a2f34b/tapazaxonupimojewozu.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c59db1bc29d---42166022521.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/54576489440.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/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=pdf+reader+for+pc+free+download+windows+xpPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB84 5312 bytes
SHA-256: 3bcb77d6e236b88d1de7dcb39ecdf2b7de7faff2a3e982d3cfa59596a1978679
font_01_sfnt_off0000ddb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB3 1800 bytes
SHA-256: 51ebeec29509b87aa858d500e37ac8853184703d07d1f913ce36d8e1dc7764c0
font_02_sfnt_off0000e641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE641 10736 bytes
SHA-256: a1a715743216b89cc094328f2c9f3780b45ca54d5af21db27703f6ee61d1ac40

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