Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfff24639773ca9b…

MALICIOUS

PDF

80.0 KB Created: 2021-05-07 22:13:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 063cbf797d39d64372f8f0f75adec3fd SHA-1: 2f6be87d832c9588ac0f24411059400c1d7802c0 SHA-256: cfff24639773ca9b4e2d13ad0f63e943f12b29bb419f28c523b80839f6ef0298
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 0.9998

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.
  • 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://nipisod.ru/strik?utm_term=hp+motherboard+price PDF link annotation
    • https://cdn.sqhk.co/kelopifagisu/jbd2Zhc/bisejofukidetomaledine.pdfIn PDF document text
    • https://cdn.sqhk.co/pubisifibuj/Xgd3Bij/37197933938.pdfIn PDF document text
    • https://cdn.sqhk.co/rolaravez/FaVhijm/download_aplikasi_my_piano_phone.pdfIn PDF document text
    • http://instup.xyz/7717006223238b51.pdfIn PDF document text
    • http://itclick.info/maxizirurunuwoorbcb.pdfIn PDF document text
    • http://ipoteka.net/16271038035wdrs1.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/8342b797-a7ec-473f-826e-b3e8643774dd/32252538278.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d96ffc1-9d29-46e7-b939-c09131e3e06e/what_are_the_different_statistical_methods.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/38bc57e0-c375-4ea3-9336-be6044d48830/what_are_the_architectural_symbols.pdfIn PDF document text
    • https://d4078116-a2d5-466f-97e6-20d899f6ca30.filesusr.com/ugd/576447_7f27384c7ae741a0b57bc0044db62540.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/27f5d13a-3ab0-44d1-ad8b-cad840521a86/pibigebolomajesuj.pdfIn PDF document text
    • https://d19688e0-347f-4d9d-8cb3-d47c6e049f3d.filesusr.com/ugd/c618e9_38dbf82ecc8f4182b9cee02927aed7d2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/99e53762-5c46-465c-960f-22e7ebfa7c47/wixejawus.pdfIn PDF document text
    • https://aca292c6-a3ee-4c96-b4c9-db15c8eca1b9.filesusr.com/ugd/cd1d52_f4a489a27fce44ff89c218cc81c8771f.pdf?index=trueIn PDF document text
    • https://6205d428-d5dc-494e-bbc3-e2236f9d811e.filesusr.com/ugd/6885a6_cadb15ba00ab4734b8d13fd27ee97633.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1201871e-2e92-45e3-9d34-a0cbfe1774cb/daresunemodorepadez.pdfIn PDF document text
    • https://1416a32c-f91c-4ec3-9c10-bfdf610c7df7.filesusr.com/ugd/76de1a_50c48038f94b49f68f0ab8ab219452c9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/652b84ea-00e0-4dbd-9ea5-e22f6aa4c09b/golds_gym_stationary_bike_ac_adapter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/41f3f504-4586-4cb6-b895-42f34cc336ed/20357313367.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a06a4e8-0aae-4ef0-bb42-3ff5735b6682/coso_framework_8_components.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BD 5204 bytes
SHA-256: 975afbac47112e203c20c02d9ee286b5b26d46635af98fef20e091fbf6a3370f
font_01_sfnt_off0000f737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF737 11312 bytes
SHA-256: b759d29c08254d7a9c7dcd45542d8a5adf2c0109abf8b90f7a204648e6bf271f
font_02_sfnt_off00011deb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DEB 16140 bytes
SHA-256: 1ffca1ef16be5e2ec436e77f9211a88ad3199dc781cb76600401cc2e2c7dce6d