Malicious PDF — malware analysis report

Static analysis result for SHA-256 174db100ec974f79…

MALICIOUS

PDF

71.4 KB Created: 2021-04-27 14:16:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: c81c47dcc0d36600eff49bcc433ca8ac SHA-1: 8b42d5ab4ba5e8cf63f101639217aada91704a96 SHA-256: 174db100ec974f79cf79005c15d9d38410fd0a89a6801671a45037628ca22833
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1539 Steal or Forge Credentials

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an MFA/2FA-themed lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • MFA / one-time-code harvesting lure high SE_MFA_LURE
    Document asks for a one-time code, authenticator approval, or MFA confirmation — consistent with credential phishing kits that steal session tokens or abuse multi-factor authentication
  • 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://natsihwa.org.au/sites/default/files/webform/80931084074.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/25596831819.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/kafavepovimurajubek.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/71260674720.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/bedadijone.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/dizage.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/64517041799.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/wozupidojenebimovom.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=does+directv+work+with+roku+tvPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/tujuxegagisezemesolut.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/43157208480.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/delibenapu.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cdc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC9 4776 bytes
SHA-256: 94a252160c66c400bb9fd016a05359d7dc4bb57f0069e0576cedf2474fd8a927
font_01_sfnt_off0000de35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE35 10700 bytes
SHA-256: 9cb01353295dbfb3e358c56672b8128edf2fe3f6ea130b84c46fca8d0df217b0
font_02_sfnt_off000102c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C9 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3