Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1874090f8b26546…

MALICIOUS

PDF

75.6 KB Created: 2021-05-27 21:09:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: d6930b3d38518da575160ecab5c39dba SHA-1: 1157eea9e6fec8024719be06e7e41812a1041855 SHA-256: a1874090f8b2654642d25ecf7f296ab63be05da09e4d41ab14e5701e0390a8d8
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URLs, such as 'https://jacksth.ru/strik?utm_term=sequencing+events+in+a+story+worksheets+grade+3', are likely used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://jacksth.ru/strik?utm_term=sequencing+events+in+a+story+worksheets+grade+3 PDF link annotation
    • https://forabuluzasojar.weebly.com/uploads/1/3/5/3/135303956/d4ebd3.pdfIn PDF document text
    • https://rikidunojig.weebly.com/uploads/1/3/4/4/134488605/56287c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4502511/normal_5fe4e1903c1c5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4367925/normal_60001472da22f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419633/normal_605d6679217ba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426967/normal_605f9b18b1359.pdfIn PDF document text
    • https://rufuwoja.weebly.com/uploads/1/3/4/7/134735928/492941.pdfIn PDF document text
    • https://litaxavuve.weebly.com/uploads/1/3/4/8/134848922/jowusid.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415946/normal_5ffa9b3db2d60.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468571/normal_6030325c33203.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421474/normal_5fd2e6beb04df.pdfIn PDF document text
    • https://rozuguki.weebly.com/uploads/1/3/0/7/130775318/3631430.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403128/normal_5fdeed1f46a07.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/995f4e34-0591-4316-b25e-7cddde7f09ac/97223143907.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57a6a85f-8a49-4049-b27a-5d0430410cb3/sitiz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aaebfde5-c34e-4b78-8f6c-4911ab9de939/jewoliwapewumifiref.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d61d692b-9933-4e96-8bd1-04f2cea5b0f8/wordpress_login_not_working_after_url_change.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8490afa-de6c-4a74-927a-fc1fd54a19bc/canon_rebel_t4i_manual_espaol.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7555fc74-4095-4e0f-b6cb-7617701f6ff9/richmond_water_heater_lighting_instructions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/985703c2-03d8-4684-8c97-30ac73e11d07/bojawejepojo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93615b52-8b25-4053-8a53-8c122436e7b0/is_matlab_a_programming_language.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d82fc613-22df-46d3-8e14-912e087020ca/braun_series_9_9290cc_bed_bath_and_beyond.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e7ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7FF 5880 bytes
SHA-256: 60da40300733d66aa6753608818e9ca955acf5905c9b7834002704c5eb2d3f36
font_01_sfnt_off0000fc17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC17 10744 bytes
SHA-256: 7d98b0154a679715608c72599f201a474f495dee2483c0c6366ed94270fe8fbe