Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a9bb62ba8ca4e6…

MALICIOUS

PDF

78.7 KB Created: 2021-06-11 05:58:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 20a2e3ad2e578e613764d4fb4c2ccacf SHA-1: 086b01868be01ec5e31098fd3197e8ce62578c20 SHA-256: d8a9bb62ba8ca4e66e12eb9ca6ce9b4ad0e013586d93780d5329cb3fb4016f79
254 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple critical heuristics as a malicious redirector and link farm, indicating it's designed to lead users to harmful sites. The ML classifier also strongly indicated maliciousness. The embedded URLs, such as dafemum.ru, are known malicious redirectors, and the document body, though heavily obfuscated, contains text related to 'nutritional information' which serves as a lure. The ClamAV detection further confirms its malicious nature, identifying it as a phishing trojan.

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://dafemum.ru/123?utm_term=winking+lizard+tavern+nutritional+information In PDF document text
    • https://kejarokelevu.weebly.com/uploads/1/3/5/2/135297316/gosunukaligelowuwig.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450733/normal_6063b06209d5d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484365/normal_5feb62057dcb1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417664/normal_603f42974ed7c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367644/normal_60c2ca5201690.pdfIn PDF document text
    • https://wuwinotidewav.weebly.com/uploads/1/3/5/3/135349353/8503027.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4407064/normal_5fcf4ffa886ea.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386609/normal_6009ef3ea9d3b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426558/normal_604fdb058939e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4491450/normal_6002d2d2e1d06.pdfIn PDF document text
    • https://pibowalemarume.weebly.com/uploads/1/3/1/1/131164440/babofanupekomax.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405197/normal_5fd9f24ad060d.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/310bb634-a729-4767-82b6-0a8a272b97f5/42121529020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b051f2b1-d690-4bff-a4b0-c9107475cdf3/how_to_connect_soundlogic_xt.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b718a379-680c-44db-8384-7018e942f90e/tafikalodejow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14100090-f527-4336-b813-83f904894f00/wujatosagevuzovidogepube.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/58aa7af7-e3fc-4bc2-8d11-601a56771476/77082380945.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/971d0fd2-41d8-457e-9762-45a26278b564/why_wont_snow_blower_start.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_off0000f3b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B2 5236 bytes
SHA-256: 9be3114638a55a64ce38ea9d6a3ae0478f5e3b47bef21c5c1292b8a69e86936b
font_01_sfnt_off00010596.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10596 11280 bytes
SHA-256: df697af62eae90866dcdfb83cb65dc098a80d4f8031fa7a92ba4b4652ea87d35