Malicious PDF — malware analysis report

Static analysis result for SHA-256 8821e80126222422…

MALICIOUS

PDF

85.4 KB Created: 2021-04-07 07:58:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 40f2d0ddc177c271210917fcba64321f SHA-1: 75ba62adacc016034fd65c883d46b31f4f93ced8 SHA-256: 8821e80126222422a86af35214b5131b168bfae9335dc2539d01f4ebeb3a1e9c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. While no scripts were directly extracted, the PDF structure and embedded URIs suggest an attempt to redirect users to malicious content, potentially exploiting PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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 http://seiary.com/sites/default/files/webform/rec/netugapufuzutazegiwiwivi.pdf In PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/fezijorimofilafomifum.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/86196288468.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/69174909787.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/razodogodipuvubetixem.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/nozixedexifanozavarojiro.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/wajuso.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/80098342864.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/mulakipezumaxusilexuvu.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/99544266771.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9027254294.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/44923699615.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=amarakosha+slokas+pdfPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/moxogugudufagelo.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e23e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE23E 4772 bytes
SHA-256: 04f69d32410bcdf0cdafd972465890afba4825b5985efebbb9e66ecd67b646d0
font_01_sfnt_off0000f263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF263 10836 bytes
SHA-256: 096e33c53a78547324bdb17cb30b5dd4efdec91f9e10d488690703bb5407b805
font_02_sfnt_off0001162d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1162D 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
font_03_sfnt_off0001242f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1242F 11216 bytes
SHA-256: 789c633e4d49008bc21abf6eeec0b5d48312049fe26f641eedbc9b1cdd6041b6