Malicious PDF — malware analysis report

Static analysis result for SHA-256 57f623cdc7693af2…

MALICIOUS

PDF

67.8 KB Created: 2020-11-23 06:45:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e1a7dd1844c0aa8009f303fe851fb5bc SHA-1: d2b5e2546af6f277e9b065e6cb33e0d889b228b5 SHA-256: 57f623cdc7693af2ab46312e6ebd14d1fe2a07f541121273ba3fe3ccca547f0f
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a significant number pointing to potentially malicious domains, as indicated by the 'PDF_SEO_LINK_FARM' heuristic. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing or malware distribution attempt, likely using spearphishing as an initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://trafffi.ru/123?utm_term=acids+and+bases+worksheet+model+1
    • https://sonadenazutimiw.weebly.com/uploads/1/3/4/6/134654654/28d80f081fe43.pdf
    • https://cdn-cms.f-static.net/uploads/4381541/normal_5fa5120dcc0de.pdf
    • https://cdn-cms.f-static.net/uploads/4446781/normal_5fa75849d09e0.pdf
    • https://cdn-cms.f-static.net/uploads/4403271/normal_5fb03824595d1.pdf
    • https://cdn-cms.f-static.net/uploads/4368991/normal_5f8c128a49081.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/wonoti/fetal_alcohol_spectrum_disorder_fasd.pdf
    • https://s3.amazonaws.com/leguvefu/wunixaxume.pdf
    • https://uploads.strikinglycdn.com/files/89e6ce9b-28ff-4e04-b654-05c4a4a6505a/serofawe.pdf
    • https://s3.amazonaws.com/temuxow/fosazidotawakexigovam.pdf
    • https://s3.amazonaws.com/pibabopuduj/24263109691.pdf
    • https://uploads.strikinglycdn.com/files/430be845-1ddf-4d03-a1fd-5a4e496e23b9/dobamajuwipibonime.pdf
    • https://s3.amazonaws.com/mesixadelomomo/98786882278.pdf
    • https://uploads.strikinglycdn.com/files/18ce71f4-40f7-4a30-83df-913032f0cc35/miracle_question_worksheet.pdf
    • https://uploads.strikinglycdn.com/files/d4a5d11a-ac99-4752-b151-d9a461f4d0fb/free_disc_burner.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc1e.bin
83b57475fbfa51bd63231993389e9891f91b3010f56d7cdfb5182e76723a83bd
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC1E 5516 bytes
font_01_sfnt_off0000deca.bin
8184a4269077460dc567986a2db01b4780e0e6718fe02eaec68fe3f3e23b2481
pdf-font-stream PDF embedded font (sfnt) at offset 0xDECA 10492 bytes