Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecf03df765c7ba54…

MALICIOUS

PDF

81.5 KB Created: 2021-03-09 21:41:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 7535c2304a44533214e9c666d2def599 SHA-1: 1516b1b96cdc49392f186fb4b8de8fdbb46cdabe SHA-256: ecf03df765c7ba5430ac2b6ccd3f2951de0a28343352d4868f220ff3b7663eba
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://kuzutuzo.ru/award?keyword=surgery+mnemonics+pdf+free+download PDF link annotation
    • https://kanodofeju.weebly.com/uploads/1/3/5/3/135325650/3597332.pdfIn PDF document text
    • https://cdn.sqhk.co/nuzinipaz/nmghwja/gigidisoveze.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414486/normal_6039f2ca8b658.pdfIn PDF document text
    • https://liletizotefos.weebly.com/uploads/1/3/4/2/134234842/japuve.pdfIn PDF document text
    • https://cdn.sqhk.co/madagijoj/TighnSz/buloril.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425908/normal_600921b7eecec.pdfIn PDF document text
    • https://cdn.sqhk.co/pewesopefim/3geggek/6847329856.pdfIn PDF document text
    • https://cdn.sqhk.co/falupuvevore/QQxdRib/chrono_trigger_android_apk_full.pdfIn PDF document text
    • https://defelidiko.weebly.com/uploads/1/3/1/0/131070982/mopukutipori_debowofewuv_wikujupatag.pdfIn PDF document text
    • https://dataremidesop.weebly.com/uploads/1/3/4/6/134697992/xowokaxirokoxe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4471467/normal_5fc5ea58846f4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485696/normal_600b62096069d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420237/normal_601516aa12c06.pdfIn PDF document text
    • https://fedalovojuxunod.weebly.com/uploads/1/3/0/7/130775560/jumefi_xowekemapigi_wutifaler_zirapag.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b1310c2e-43e5-4197-ad92-90db0908cffe/sarilew.pdfIn PDF document text
    • https://c03439ef-6557-4199-865e-586791a52b6c.filesusr.com/ugd/6bb4a2_59c07c46323c4588b953205839e694bc.pdf?index=trueIn PDF document text
    • https://569961a5-e6b5-462d-8b38-7193d5e7b20b.filesusr.com/ugd/a37a2e_e01eeb22ff024ba9bc16019e0749d7a1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xumakomowi/39111972415.pdfIn PDF document text
    • https://b4095e1f-5e43-4c35-8b28-ff0c3185c247.filesusr.com/ugd/9cc3de_4a402b59253141fabd4e2e4c443c9c78.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b2df0c8-4733-47de-9394-98ec9a6b33ff/sujapazusafijoxunufujog.pdfIn PDF document text
    • https://d064ede3-316f-4d13-8ec5-014b2136b3bd.filesusr.com/ugd/154db6_64fd9d31754440f4ad1935d66b9b4a3b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gapivegek/ruwazogunonizuxakex.pdfIn PDF document text
    • https://5a6df620-610b-4d6f-8f1b-71e936bb70bc.filesusr.com/ugd/1f5cef_6b64d69884e14935930e4849292d31eb.pdf?index=trueIn 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_off0000fcc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCC0 5772 bytes
SHA-256: fe795c1182a79ef9b227b4e82954c0c6e53ae19b5b435d381331715c95bf80cb
font_01_sfnt_off00011070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11070 12396 bytes
SHA-256: fa268072f2ed6b61bfbc426449fad55f717f3267f6a0a03f74224e46a43d95b7