Malicious PDF — malware analysis report

Static analysis result for SHA-256 d91c8c6f084b2df4…

MALICIOUS

PDF

75.6 KB Created: 2021-04-25 18:59:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 346ee353e574f9d7393298da8ed7e349 SHA-1: e4d0f971d5c56074996dd2a7f59f983dd2897926 SHA-256: d91c8c6f084b2df45b1a25599f7be23eeaddd0cadc859492297c843b4f41b8a6
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous embedded URLs, many pointing to potentially disposable domains, suggests a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution lure, likely leveraging embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.mothercare.ro/sites/default/files/webform/resumes/28941778760.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/604022749.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/pagasumoxozodaxatukaliwus.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/89533113822.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sowasipaxezok.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/jebumimebugamoto.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/42416127327.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/jizexatunurometubukos.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/makepepatamizozixijefawop.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/tarutemivejumariwara.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/34869944823.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/sujuxot.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+to+make+drawings+glow+on+procreatePDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/pagilavamuvawasaxega.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/16157352895.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/50075528518.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_off0000e1fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FC 5508 bytes
SHA-256: 6ae3e5d918a5ce90e0fb14fd2d7955038458aa948d15d8b369fb6698c2d94b40
font_01_sfnt_off0000f4b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B4 14104 bytes
SHA-256: ec34f50c89bfe2dd988d9487359a03ee9fcf60edf0588f9d87e13939ccfca825