Malicious PDF — malware analysis report

Static analysis result for SHA-256 91da1baf1f9f2521…

MALICIOUS

PDF

91.6 KB Created: 2021-06-24 05:04:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 731b85daf03d2746d569d8591aa1fcb1 SHA-1: 79ced8ac45cb18f58ee89ba258737920a78052ab SHA-256: 91da1baf1f9f2521db7e7f0d331f68face644ce98a70c89c68783d8ed5e933f5
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs that point to compromised WordPress sites, likely serving as a link farm. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to lure users to external resources. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee2eb0fea6---87179782051.pdf In PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/r5ha4l5j4sbd01qn9p5c4orul6/20175414518.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb386b5cf9---84697361504.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079039e160b3---72957030672.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c94fcc66200---fifikefepufupifafegaz.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc1b63b464---74610627988.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b083e54aa47---ritonomem.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/r14maf19977ogr8gm0b3lootl5/15659727779.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e44ea9b258---53426729523.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d17a56d9c4---67597677991.pdfIn PDF document text
    • http://kaitosushisb.com/uploads/files/nulogojiseraki.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/p1hd9psnh19bthndghbo3gfnbe/82996380746.pdfIn PDF document text
    • http://polletnv.be/uploads/files/5051382049.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a396ea1ea74---bedifon.pdfIn PDF document text
    • http://tcsm62.org/uploads/news/file/37894331399.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160887d280d767---46284674861.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/cv9VXjIrmdE/uplcv?utm_term=wolf+totem+book+pdfPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE80 18828 bytes
SHA-256: ae49465c56f8ae6b87415d88ded47ef4fd0545c8cd588d6ca8c9d1213ab48550
font_01_sfnt_off00012a4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A4B 4920 bytes
SHA-256: 75f861327beb339c3dd29ae86f76a84f9afc3d431595b9deea94ac9d3bd65dde
font_02_sfnt_off00013b05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B05 11144 bytes
SHA-256: e3ef78e45485f9a945747aa5aa0d2e4401a11b18024195581d156aeb08986c0e