Malicious PDF — malware analysis report

Static analysis result for SHA-256 89f9eed43a062378…

MALICIOUS

PDF

79.4 KB Created: 2021-03-20 19:21:38 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 5fafee2295f3cc283908745fa75c6ee8 SHA-1: 8746088f5eff38f276da67e77f38cfee66dbac06 SHA-256: 89f9eed43a062378a94e6cc3bddd540402f460e6d211e43b86e2f5d9cf1e6181
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic analysis reveals it functions as a link farm, containing numerous external links to other PDF files hosted on various domains, some of which are disposable. This technique is often used for SEO manipulation or to distribute further malicious content. While no scripts were extracted, the PDF structure itself is designed to redirect users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cdn-cms.f-static.net/uploads/4388274/normal_602218c0cdaed.pdf In PDF document text
    • https://static.s123-cdn-static.com/uploads/4471682/normal_5fe2df92dd431.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493917/normal_60433fca5f488.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477863/normal_6018e484107f6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416143/normal_6049a9249cf77.pdfIn PDF document text
    • https://cdn.sqhk.co/junigofulum/ULoiihe/hockey_manager_19_2007.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494431/normal_5ff3a9217334d.pdfIn PDF document text
    • https://cdn.sqhk.co/fofotixoz/i3hgieL/outlook_email_as_html.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/wb/ENAH/~3/0IJhScypsXo/wb?keyword=java%20game%20code%20examplesPDF link annotation
    • https://4a39c6c9-989b-4d11-b2d8-cc0becc7f193.filesusr.com/ugd/ef0078_912685a2f7fd4c63bcfbf555edddcff3.pdf?index=trueIn PDF document text
    • https://ddb281da-11d2-423e-b83a-408ecf1f607f.filesusr.com/ugd/9db61c_fdf28641ffa34df994ae273847e4c982.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ce3dd33e-6e23-493b-874e-164ac8c6fd2b/93462088877.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04443a46-9bd4-42fe-9833-b174cc11279c/66135376999.pdfIn PDF document text
    • https://73856814-13bb-4d44-aeaf-752cce6ba6bd.filesusr.com/ugd/a0d21a_31c3fa9f672e49c18e86e696be9c3b6d.pdf?index=trueIn PDF document text
    • https://3ea853e4-7f2b-4fb0-9229-b04907a1e321.filesusr.com/ugd/d94095_d21861574f08494bb49d036d33c53833.pdf?index=trueIn PDF document text
    • https://56db2a4d-09ce-4ff6-a558-abb1d6727cd4.filesusr.com/ugd/003b86_c761f77a598f4c319f53567441fb66a5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8534faa8-2433-40d8-a52f-9f976a4fe66c/which_dirt_devil_vacuum_is_the_best.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32ff1a67-a892-4ecb-b574-1c5015a1be02/68473286776.pdfIn PDF document text
    • https://c183b790-cb34-49aa-848e-1a9f2b14dda3.filesusr.com/ugd/d8966e_c2bcf485bc2f40f49ce9cf1152f325a7.pdf?index=trueIn PDF document text
    • https://83372c7a-1065-4b07-8284-b64562b46e84.filesusr.com/ugd/035489_6b388a92865f4c89b5cbfd3642bd94de.pdf?index=trueIn PDF document text
    • https://b1b1ed1d-a631-407f-b8a0-2f609481a9c2.filesusr.com/ugd/3e5895_a2de679ea4f04fb8be1b044576f8b27e.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_off0000f428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF428 5416 bytes
SHA-256: 5aee66e35d464790f00a9e48ec76d77bd28bbabed50ac125731a9141c176d7e7
font_01_sfnt_off00010694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10694 11916 bytes
SHA-256: d20fde15098663991943de7e5ca662f525b136dbf6478c0c68298cfbb3bb0507