Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c3b2228fb00c664…

MALICIOUS

PDF

44.8 KB Created: 2020-10-15 00:55:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 315d08e2e6a703878c005bb1f77d5d03 SHA-1: d4f8ec6e83d0eb915cbef5715b35f6a61d54a9a1 SHA-256: 4c3b2228fb00c66442f90214b16bdabbe192d7ce04397be9297cc531e3f8a85c
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded links, many pointing to disposable hosting and redirector services, indicating a link farm or SEO manipulation tactic. One prominent URL, 'https://gettraff.ru/123?keyword=comprehension+worksheet+for+class+3', is flagged as malicious. The document body, though partially corrupted, suggests a lure related to educational content, likely to trick users into visiting these malicious sites.

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://gettraff.ru/123?keyword=comprehension+worksheet+for+class+3 In PDF document text
    • https://boguvetasitob.weebly.com/uploads/1/3/1/3/131380850/8a68c5dc19.pdfIn PDF document text
    • https://rabifupokuwu.weebly.com/uploads/1/3/1/1/131164250/belufokomodosijimona.pdfIn PDF document text
    • https://site-1040280.mozfiles.com/files/1040280/1551201220.pdfIn PDF document text
    • https://site-1039180.mozfiles.com/files/1039180/araba_yarlar_apk_indir.pdfIn PDF document text
    • https://site-1039610.mozfiles.com/files/1039610/65268897854.pdfIn PDF document text
    • https://site-1038844.mozfiles.com/files/1038844/49655873394.pdfIn PDF document text
    • https://site-1041782.mozfiles.com/files/1041782/tujawaralobokox.pdfIn PDF document text
    • https://site-1039829.mozfiles.com/files/1039829/bavemazowutawesebidaj.pdfIn PDF document text
    • https://site-1038492.mozfiles.com/files/1038492/sixazajikifaxulemuxojo.pdfIn PDF document text
    • https://site-1037916.mozfiles.com/files/1037916/26521318942.pdfIn PDF document text
    • https://site-1042509.mozfiles.com/files/1042509/43612255434.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/6e5e796c-fc3d-4eae-b2e2-3c1e8cd25784/dokuwipom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98f6f35b-9950-4269-bcf6-5092b2b337c7/zojopezegevuru.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bdf72d91-040f-4746-b208-1bb6b8aca0eb/monufidejaxofipu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6bbb4d87-84f0-49df-b176-4bbc7cfb7751/43495456112.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5ca28c6e-f7db-4c92-804b-a4608fd899ef/zapepajam.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cc506d2-774c-4c41-a1be-910e81d825bf/11346308521.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7685d1d0-c70f-4a9f-a905-f2e182e1be18/duwupokuvajeguxezalovu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35105a6b-af98-4df4-a49a-dea310e4a128/ravol.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_off00006f85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6F85 5480 bytes
SHA-256: 6ae5e01525ebc01ffd8ff5fed354f4984b3e3f1d71c258d4186a386687a2f407
font_01_sfnt_off0000820d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x820D 10744 bytes
SHA-256: 122958d681a6a156de14515b5982346dc5b1177c6868f9c22237ee63e7be0f7b