Malicious PDF — malware analysis report

Static analysis result for SHA-256 66bd1df5b2a99f88…

MALICIOUS

PDF

72.0 KB Created: 2021-03-25 12:41:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 3780cdd317f03c66818dcd339b79ae79 SHA-1: 6f05019168f496ab4dc31e78229124f278e1f133 SHA-256: 66bd1df5b2a99f8881e013340ff2f8b7c77a0b539ff63ac5d6aa2028ca62ee2f
254 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious redirection and a link farm, with a critical ClamAV detection. The embedded URL 'https://yafferge.ru/123?utm_term=bangla+song+album+video' is identified as a malicious redirector, likely used to funnel victims to a phishing or malware distribution site. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs.

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
  • 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.
  • 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://yafferge.ru/123?utm_term=bangla+song+album+video In PDF document text
    • https://tugadebijo.weebly.com/uploads/1/3/4/0/134042488/8d074.pdfIn PDF document text
    • https://cdn.sqhk.co/xojelumegasi/hfsiaii/35449418547.pdfIn PDF document text
    • https://cdn.sqhk.co/zijigemeworu/lgejjlS/yellow_pages_phone_number_reverse_lookup.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4386333/normal_6003a1561c2dc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379369/normal_5ffb408e2aa55.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369646/normal_604f57a9dce6d.pdfIn PDF document text
    • https://cdn.sqhk.co/navotezive/hirUies/nba2k20_locker_codes._org_vc.pdfIn PDF document text
    • https://fezuwarojeti.weebly.com/uploads/1/3/1/3/131383544/445212.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455375/normal_6041836d14897.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/49a0011b-b459-473f-aff1-5e160e630e8d/sermones_adventistas_en_power_point_para_predicar.pdfIn PDF document text
    • https://s3.amazonaws.com/watajive/advanced_search_techniques.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f2e122e2-285b-4a97-b473-b9e8e59c82e8/sijagilofolizoxaraf.pdfIn PDF document text
    • https://s3.amazonaws.com/jeduzizonox/how_to_write_a_case_summary_for_court_uk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/064d5de8-b3d7-4b98-bbc0-506b38eb1ed2/intellichlor_chlorine_generator_inspect_cell.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b169a3ad-9bbb-4e75-881f-338f538861ac/skyrim_how_to_meet_the_dark_brotherhood.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3ec876e2-5be5-493d-8b5a-3623c93cc485/43665480892.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74ee1582-9628-46a5-9901-62a5f88d097a/30925770496.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1192f623-a98c-422b-b66b-e8ad393c548c/sofibemuvunivuwizuza.pdfIn PDF document text
    • https://s3.amazonaws.com/fowonaxul/arere_manase_song_ringtone.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_off0000db73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB73 5300 bytes
SHA-256: 7c2fde13109f63a649fb8a72644f00e253c75853eae4fadc31445f5f1d089a23
font_01_sfnt_off0000ed6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED6F 10932 bytes
SHA-256: c20977ccaff4a08e75c2489ebf5896141b54296e0270473fc85331c3f85215c0