Malicious PDF — malware analysis report

Static analysis result for SHA-256 81067876b94b92ed…

MALICIOUS

PDF

66.4 KB Created: 2021-04-04 00:38:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 0502a321aae0dee0f76d0baf1cad8a70 SHA-1: de6950a964b3e2bf775ce3a7d543d2980b1ef856 SHA-256: 81067876b94b92ed695dd62cf90df43d18bc41204d3caa871fcdb19d0006abb2
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which are SEO-redirectors, indicating a link farm or phishing attempt. The primary malicious URL identified is 'https://golowaki.ru/wix?keyword=rock+cycle+webquest+learner.org+answer+key', which is presented as a lure for educational content. ClamAV and ML classifiers also flagged this PDF as malicious, specifically as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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.
  • 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://golowaki.ru/wix?keyword=rock+cycle+webquest+learner.org+answer+key PDF link annotation
    • https://kinijenu.weebly.com/uploads/1/3/4/6/134641264/pifukis_wilusaj.pdfIn PDF document text
    • http://kewokuxumuzig.medianewsonline.com/pozedemav.pdfIn PDF document text
    • https://sifobidegi.weebly.com/uploads/1/3/0/8/130874382/4c7b5c3.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/aef8e9b9-1d75-4e58-8351-211d1921093d/guitar_songs_tabs_and_chords_for_jingle_bells.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9d7a326e-0d51-4205-a083-11136be40333/adobe_illustrator_classroom_in_a_book_2020_lesson_files_download.pdfIn PDF document text
    • http://timojodabemisux.myartsonline.com/39238945315.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/681ef872-6142-4fd7-819e-2436c8a41fbd/sudimilulole.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d5bbbae8-3a92-43ae-84ee-8cd2dbb78614/88898089845.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bbdb6ee2-c4fb-4115-bc22-0189ce5e787a/zifeguvigix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b339b85b-7380-4422-82ac-e5c1f6cc5be5/17331790619.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bdcb6f95-a603-46b6-8475-ab26e9c02dc2/lawodokikabewaxakefiw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f666dd63-0638-4223-8874-6e205160f78a/93191817313.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3defc23c-0aa2-4d9a-aa61-1b6d27113635/anger_management_books_best_sellers.pdfIn PDF document text
    • https://e2604e0b-f95a-4acb-b53f-a7db3827b2a1.filesusr.com/ugd/225520_da38cf217ed04c2e8d76743e1ca4a0fc.pdf?index=trueIn PDF document text
    • https://6680615c-3592-42a6-94f3-b98e474b5330.filesusr.com/ugd/252546_818c5ff0dd354c89bb119b459b3005aa.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4b77f66-05a0-4376-a6c6-5a3ae8b4cdfc/95152021325.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3c2f484c-2a2e-4e6d-89c9-b21a9fe244bb/jukadevatokiz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/00b43618-40eb-429f-aefa-74a1b2b64278/define_zone_of_proximal_development_example.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_off0000c54b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC54B 5532 bytes
SHA-256: a7af69aeb53aeed7b41d8947f8441e44d1bc4b8b37fa2ecec2cd9ed894341f35
font_01_sfnt_off0000d85c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85C 10552 bytes
SHA-256: 63ce0b231c3b4745c47f613c41d64f293cffe368b12fa2432ef0a567775f3daa