Malicious PDF — malware analysis report

Static analysis result for SHA-256 3830712b3f5de0b3…

MALICIOUS

PDF

74.4 KB Created: 2021-05-29 07:22:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 4d5e6b77d2147c2c38182a2b8c7f499a SHA-1: 191c228cd6e7c14147b098595c0c62b777a65ad4 SHA-256: 3830712b3f5de0b30750e6cfc1e39a99a811841bb6bd593b7f07c46720a64f29
196 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to SEO redirectors, indicating a link farm or phishing campaign. The heuristic PDF_SEO_LINK_FARM and PDF_SEO_UTM_REDIRECTOR_LINK strongly suggest this. The ML classifier and ClamAV detection further confirm its malicious nature. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing lure designed to redirect users to malicious sites.

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
  • 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://gimoguvi.ru/123?utm_term=navy+football+uniform+history PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4417418/normal_60583db2bf3f3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465127/normal_5ff0ba092eec2.pdfIn PDF document text
    • https://buvedanazifom.weebly.com/uploads/1/3/4/8/134876279/motalome-zolutatasuxit-vatuxo-sowij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376612/normal_601e512b2f1ce.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378153/normal_5ffb908a0def2.pdfIn PDF document text
    • https://tinubuwetoka.weebly.com/uploads/1/3/5/3/135325034/c6a26.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490528/normal_60501e9b3181a.pdfIn PDF document text
    • https://momekefu.weebly.com/uploads/1/3/4/8/134850451/d767d247e737.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/6526a2be-8a9c-4c95-9b11-12eed0f75854/how_to_calculate_credit_to_gdp_gap.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e624b4f7-f5a3-458d-86a3-4b1f60b973cb/my_talking_angela_2_game_video.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/145bb59e-9ad5-4e4a-a2b9-aff397950c0c/what_is_the_role_of_a_prophet_in_the_bible.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6db82a28-20af-42ee-86c9-6005cdf749e4/how_frequently_breast_milk_is_produced.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4b4be5cb-3a15-4571-abb9-823e392216c1/zemanava.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a717c08-bd0d-4969-92ff-cf670c14c1f5/fl_studio_os_x_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/906800c9-13d5-4216-a386-2535ece40ccf/depth_perception_eye_test_meps.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f78ad5cd-3aba-47aa-a365-c5634524ba6d/does_apple_offer_benefits_to_part_time_employees.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_off0000e48d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48D 5280 bytes
SHA-256: d41cebc1c35c63e19032d90fe682d52f0947eac8c045ac01239415b130107bc6
font_01_sfnt_off0000f66c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66C 11052 bytes
SHA-256: 87fef526b28da52e37d2fd46a3aa6ac79191c3d65d2d8d051968375f51c1b662