Malicious PDF — malware analysis report

Static analysis result for SHA-256 271cb114fb0d81a5…

MALICIOUS

PDF

69.3 KB Created: 2021-04-25 11:21:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 7946366079cbcf86b835e9c4810c76d2 SHA-1: 4fb1e274127d4ce32e1ffe6fb6680e368a8e1795 SHA-256: 271cb114fb0d81a545551eff12b7faaef8f18c92984869127b5005e1d1887659
126 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to potentially malicious or link-farm domains, suggesting an attempt to redirect users to a compromised site. The document body, though heavily obfuscated, appears to contain a lure related to job interview questions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://www.mainephilanthropy.org/sites/default/files/wimatetomowitiki.pdf In PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/74543186253.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kubuxodadiwozubak.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/11252708720.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/99469138220.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/povufukawonafano.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/93477879009.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/ziwisotug.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/dexifivoneput.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/zavemazawutojene.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/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=what+are+the+interview+questions+for+hr+positionPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/68382108709.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/ziwilijevugibapuvoboka.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD552 5248 bytes
SHA-256: 7f00b2e9bb7fd5844d4e9f247ffb719f829f7f62da1c062f54ffd067106ea0d0
font_01_sfnt_off0000e748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE748 10096 bytes
SHA-256: c688f769fba69f161cf4a30733de5a1638f60116d5814b7f3d6aba692a06ea03