Malicious PDF — malware analysis report

Static analysis result for SHA-256 a422e315b13b35da…

MALICIOUS

PDF

72.2 KB Created: 2021-04-07 04:22:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b462a91b6f329acb0963ba67ee42c118 SHA-1: 7f7a50cfa91d60aff8063c78652ce4f516e8cc49 SHA-256: a422e315b13b35dae379d805dd0c0204ba6c85b3ec3bb0b5486aee9dc4065d41
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable domains, characteristic of a link farm designed to redirect users. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a high likelihood of malicious intent through deceptive linking.

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.osgeurope.com/sites/osg-corporate.dev/files/webform/10654010608.pdf
    • https://www.pharoxglobal.com/sites/default/files/webform/70645978292.pdf
    • http://russian-ice-spb.ru/sites/default/files/webform/files/loxigexaxezirizedud.pdf
    • https://www.enwidth.com/sites/default/files/webform/resumes/21555212736.pdf
    • https://www.pharoxglobal.com/sites/default/files/webform/7322176875.pdf
    • https://ambrose.edu/sites/default/files/webform/rebunedirewe.pdf
    • https://www.mothercare.ro/sites/default/files/webform/resumes/jevosofotabotasif.pdf
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.pdf
    • http://www.pbttphtk.gov.my/sites/default/files/webform/33269367294.pdf
    • http://spotlight-sites.com/sites/default/files/webform/wokasonexigugeb.pdf
    • https://web.liderpapel.com/sites/default/files/webform/36759883892.pdf
    • https://www.natsihwa.org.au/sites/default/files/webform/21073527915.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=autoformation+windev+mobile+21+pdf
    • https://campusrec.princeton.edu/system/files/webform/febapaxugodikuzakepob.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da2e.bin
73563cb55ff25fcfbb46586e817271385204f780480d0881b7e944761f504205
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA2E 5476 bytes
font_01_sfnt_off0000ecd3.bin
f8941852194e3f2b14d9acbed3001ccdaeaea03d9971de0ddc3857ecde8ef333
pdf-font-stream PDF embedded font (sfnt) at offset 0xECD3 12740 bytes