Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac35a4522ecfa716…

MALICIOUS

PDF

69.4 KB Created: 2021-04-12 07:04:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 9cc176956f6ac48f8ada44397cbddb9b SHA-1: d30355e90690ad079e2160bd0cca62eb6f8be1ea SHA-256: ac35a4522ecfa716177b3c6c4cc198c00a8831a689b5187fef8154193a3f6381
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as a phishing trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, with one specifically identified as a link farm on disposable hosting. While the document body is heavily obfuscated, the presence of multiple links suggests an attempt to direct the user to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://klm3fg.grhosting.cz/sites/default/files/webform/files/30253637425.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/9979090083.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/wefegazeketalewawer.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/59286961246.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/fajabenofedutetigolexid.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sumeli.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/fifomibap.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/41164207556.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ratasivovo.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/kixeje.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/28911573484.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sakobonomoduriv.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.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/~3/1xuhb7AK25c/uplcv?utm_term=dublin+murders+bbc+episode+guidePDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/vojevo.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/fumegefexuwonadijot.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/popikinof.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_off0000d253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD253 5320 bytes
SHA-256: 73a98547a3a692aa1f3adb0e3d381b8e574ee4c5b7aab3f529016d47813524cc
font_01_sfnt_off0000e454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE454 10664 bytes
SHA-256: 61c108a9ff6f00d240c15520f441175261a10bf4af6dd0f8dd72dbca2d71d2ee