Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e8546d89657981…

MALICIOUS

PDF

41.9 KB Created: 2020-10-15 03:17:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: dd96a34093233d3ad6e95da95f015142 SHA-1: 7c18ea72c68b6222603d3104f0c58ed6284bd777 SHA-256: a4e8546d89657981cbeadf1866c4ef44743348d5eba96e08c6bbd3cd6e278d89
184 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to disposable hosting and are likely part of a link farm designed to redirect users to malicious sites. One critical heuristic identified a link to known malicious redirector infrastructure, and the ML classifier strongly indicated maliciousness. The document body, though heavily obfuscated, contains a URL that aligns with the observed link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/strik?keyword=four+corners+cambridge+level+2+pdf In PDF document text
    • https://site-1042919.mozfiles.com/files/1042919/psiphon_pro_paid_apk.pdfIn PDF document text
    • https://site-1040383.mozfiles.com/files/1040383/48089032286.pdfIn PDF document text
    • https://site-1039903.mozfiles.com/files/1039903/xinisonodebo.pdfIn PDF document text
    • https://guwomenod.weebly.com/uploads/1/3/0/8/130873843/973289.pdfIn PDF document text
    • https://megadezatesaram.weebly.com/uploads/1/3/0/7/130776649/fezimexebitodugivife.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366313/normal_5f871471e0625.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366018/normal_5f876a1f68d05.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367959/normal_5f875fdbd1e44.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368468/normal_5f87888d67bb0.pdfIn PDF document text
    • https://site-1041284.mozfiles.com/files/1041284/67624650301.pdfIn PDF document text
    • https://site-1036939.mozfiles.com/files/1036939/99152339327.pdfIn PDF document text
    • https://site-1039607.mozfiles.com/files/1039607/89673599143.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/d3d8b995-8744-45f9-a6ab-499af78b1269/41245433180.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/03092891-7362-47a1-8250-2a2d35b788e6/wigozexipoxu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d98c750-34ab-45f6-af91-3ef3930de4f9/mifapet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/925a660c-dd2d-453e-9261-24a3a5084db1/74339456385.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c757cf14-4f72-4109-8925-348c9cc6a8a2/91898919401.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0484/5541/8021/files/zevamusepamoguloz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0482/3544/6433/files/kadenasebofoju.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_off00006616.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6616 5760 bytes
SHA-256: 56ee1dd4529a72560102064e8a23f3a50b19566ac76b1cdcaf7a9be407390025
font_01_sfnt_off000079ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x79AD 9544 bytes
SHA-256: 9608447050d9973686e77b48d6cb1b6975ae35ef3ac822da1368e8c7569e75c9

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