Malicious PDF — malware analysis report

Static analysis result for SHA-256 61398f938c9c07ab…

MALICIOUS

PDF

85.5 KB Created: 2021-05-25 11:54:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 41de40031a3f81e5abdbe0ef144c1130 SHA-1: c01e858b19a6fce67528286f7b1626f0ad6e91a1 SHA-256: 61398f938c9c07abaed4a9f0de870e36418faa0109b847dff6946955dc8b6be1
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • 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.
  • 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://zajinet.ru/strik?utm_term=isaac+bashevis+singer+short+stories+pdf PDF link annotation
    • https://zapubotugor.weebly.com/uploads/1/3/4/6/134635013/3921808.pdfIn PDF document text
    • https://zudobusida.weebly.com/uploads/1/3/5/3/135330479/caaf276c4ff8.pdfIn PDF document text
    • https://zuzilumapodebaj.weebly.com/uploads/1/3/1/3/131382406/1deb9c13.pdfIn PDF document text
    • https://wuraruxirike.weebly.com/uploads/1/3/1/4/131453605/wubokexolidaki.pdfIn PDF document text
    • https://xunopigiwigon.weebly.com/uploads/1/3/1/6/131636761/3d84389.pdfIn PDF document text
    • https://jinikegubu.weebly.com/uploads/1/3/4/8/134873825/japedodidekozib.pdfIn PDF document text
    • https://sonoredepi.weebly.com/uploads/1/3/0/9/130969061/ec3fd3e0ad7b78.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/554d1dd2-1df8-4842-b7eb-55f6febeeb57/teoria_del_comportamiento_humano_segun_abraham_maslow.pdfIn PDF document text
    • https://s3.amazonaws.com/mokamoba/16170278776.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f4a0fb8-c02f-41b6-be74-86c0bbf407a7/vogopomawusojixav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57e5b138-02c1-4720-86bd-6b6aac0b8b10/how_to_rewrite_logarithms.pdfIn PDF document text
    • https://s3.amazonaws.com/woxewiwupir/46783009974.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/623a444f-4149-4daa-8078-25b69352a280/jesavawepopunerimopivuze.pdfIn PDF document text
    • https://s3.amazonaws.com/medaliwifufugel/the_beatles_piano_songbook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d337955-f44d-4f57-981f-fbd921d7a165/john_dewey_quotes_we_do_not_learn_from_experience.pdfIn PDF document text
    • https://s3.amazonaws.com/biwubeleba/facebook_video_app_store.pdfIn PDF document text
    • https://s3.amazonaws.com/mojivikapeti/57490156991.pdfIn PDF document text
    • https://s3.amazonaws.com/sizadagazagaj/51410815705.pdfIn PDF document text
    • https://s3.amazonaws.com/wovisak/81879758005.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d01cf3a-c8e2-49e8-92f2-abcb5df2e1b1/22771276548.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0aa1084d-7014-413a-82ad-3d93cc25d49a/kowabebexusimagajix.pdfIn PDF document text
    • https://s3.amazonaws.com/patilawasu/48599767759.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_off000111e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E1 5520 bytes
SHA-256: cadd827a6c21bb813e31d99c634017f3a1d3004b75f65b8739f66c61fd25c0f5
font_01_sfnt_off000124a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124A2 10772 bytes
SHA-256: ec50abbd91711d5bb1869e708ea50ec7627db8fd49f323e7fc2d1e1fda824619