Malicious PDF — malware analysis report

Static analysis result for SHA-256 66862827bdea2cb4…

MALICIOUS

PDF

53.7 KB Created: 2020-10-28 08:58:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 81267854c5879fb2915103d696a5b26b SHA-1: 37b29950dfbffb1507f60c1733d965b99ecacc00 SHA-256: 66862827bdea2cb402b19bd3d77db06df6092c0e1b785d42a5838b02364ec16d
202 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious redirection and a link farm, with a primary URL pointing to a known malicious redirector. The document body, though heavily obfuscated, also contains embedded URLs that are part of this redirection scheme. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is designed to lead users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ggtraff.ru/strik?keyword=kerberos+the+definitive+guide+2010+pdf In PDF document text
    • https://cdn-cms.f-static.net/uploads/4411937/normal_5f93442212bac.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403263/normal_5f917dcde24eb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369511/normal_5f91ca8d62eb2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369766/normal_5f889ff058885.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381539/normal_5f95524f45ef1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372960/normal_5f88de8b9f836.pdfIn PDF document text
    • https://sibakixode.weebly.com/uploads/1/3/2/8/132814768/zixowofujij.pdfIn PDF document text
    • https://sizukejagu.weebly.com/uploads/1/3/2/6/132681884/95a3305.pdfIn PDF document text
    • https://tudupumodowi.weebly.com/uploads/1/3/1/4/131406798/fuvivuxedutizi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/simujix/72006882552.pdfIn PDF document text
    • https://s3.amazonaws.com/mijedusovineti/99711166935.pdfIn PDF document text
    • https://s3.amazonaws.com/sugaguxagu/xejasebujugebipilono.pdfIn PDF document text
    • https://s3.amazonaws.com/buxoparadazegu/cause_and_effect_grammar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1ce9751d-70f8-4ba6-8cd3-a3e5c17bb9d3/47595918379.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64c4ac80-1f63-4496-b75e-c4d41c1d293c/71494637237.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/16d9bc34-0dfc-4639-a053-87f1589b543a/paligimunujosuf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5308ae96-b459-45ef-8432-40d9d59fede1/bhagwat_geeta_in_hindi_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/586989b0-e62d-4358-bfdc-f965a1278017/kexumatugaputapopu.pdfIn PDF document text
    • https://s3.amazonaws.com/tarajix/english_year_5_sjkc_textbook.pdfIn PDF document text
    • https://s3.amazonaws.com/nowokil/puzamijodebibegotuka.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_off00008fde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8FDE 5556 bytes
SHA-256: f2664dab374efdb307a510bfa0fc583d50bfb1c3889e18c21043d154e2bda386
font_01_sfnt_off0000a2d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA2D5 11432 bytes
SHA-256: b5b32cf229a317dea7c5c09f09c4426c37220529017e8cd7deb4838451add872