Malicious PDF — malware analysis report

Static analysis result for SHA-256 62bc0736f8ae890f…

MALICIOUS

PDF

71.0 KB Created: 2021-04-21 22:05:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: b3f1b5c4b23ab2629915b6e494d944b7 SHA-1: 5fdd1068e96aad14d854fb62b099e6dc4598770e SHA-256: 62bc0736f8ae890fcbbfb9a77ace72231c96698abe555eeb90984f4c68c9b4f6
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The document body, though heavily obfuscated, contains references to wkhtmltopdf and a URL structure that suggests it's part of a link farm designed to redirect users. The presence of numerous embedded URLs, many pointing to potentially compromised legitimate sites, further supports a phishing or malware distribution scheme.

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://cicatsalud.com/html/sites/default/files/webform/sidetarebuw.pdf In PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/87400145234.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/49109440539.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/sixativitav.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/32056102714.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/8474239295.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/pefusoxewirevujilo.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/31626011693.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/lavajaruzapelusudixavu.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/90018929780.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/75468476758.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/wozupidojenebimovom.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/nunemoxajusadokuxilebe.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/30232074114.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/BvfzZFkJO3s/uplcv?utm_term=what+does+the+name+bagheera+meanPDF link annotation
    • 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_off0000d785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD785 5360 bytes
SHA-256: 4a55b45b9411d00c034f5fad85eff021f606c74feb6b3b56447350da55418080
font_01_sfnt_off0000e99f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE99F 11160 bytes
SHA-256: 71f71182cd18d17b7aa46fb0678d072994241783e0ccaf2cd4865d6d9bbea63c