Malicious PDF — malware analysis report

Static analysis result for SHA-256 40f8f8a227d8bff8…

MALICIOUS

PDF

69.2 KB Created: 2021-04-18 14:08:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: a7057fd659072fbf7ef800ec8c761778 SHA-1: 5091ea43d4c75810b701de2977470f58b91890ef SHA-256: 40f8f8a227d8bff89a46c9cdab647d3cd32e4e45ba0fe3ba9989815254d78e56
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded links that point to a link farm, a common tactic for distributing malware or conducting phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to redirect users to malicious content.

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 https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/3242210986.pdf In PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/13349970620.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/13178745316.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/17184396690.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/16921441106.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/45910982832.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9979090083.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/86303695333.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/fajabenofedutetigolexid.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/zarogoluvesiriwameb.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/34782296767.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/sinuwoxifazuroli.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/~3/6naE_Nh8_CY/uplcv?utm_term=what+goes+on+a+whopperPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/gegisikirusesikogibo.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_off0000cf63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF63 5152 bytes
SHA-256: 9b5a2df348187b9cb7670c55ad167b0429939a3b044a2e18c84558c52f0e1bbc
font_01_sfnt_off0000e103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE103 11644 bytes
SHA-256: 91a3f6de440700e950179a80e34db43a870775b0edb4ee1714aa6eb0259d05d9