Malicious PDF — malware analysis report

Static analysis result for SHA-256 a26f0b3b0c50006f…

MALICIOUS

PDF

74.4 KB Created: 2021-09-03 01:13:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 43ca353126293e0edc772200796f7b36 SHA-1: 9a8e477cdb5681b1512cb6142ccacacd563352c1 SHA-256: a26f0b3b0c50006f8125f67993f1b183a3e5d86ab131cacae9fd3bfd5f8b553e
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm pointing to external URLs. These URLs are hosted on various domains, some appearing to be compromised WordPress sites, and one directly uses an IP address. The PDF's structure and embedded URIs suggest it's intended to redirect users to potentially malicious content, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://smidgel.ru/uplcv?utm_term=abbreviated+injury+scale+2005+manual PDF link annotation
    • http://zonwering-nederland.eu/ckfinder/userfiles/files/gewonudu.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/xazinawelof.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/161138806c23c4---zejazenug.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9e32ecaeb---3427766918.pdfPDF link annotation
    • http://francescofesta.it/userfiles/files/vosawel.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/64d55202fe473c69a9fe6815aa5400b1/20135057951.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/58178502959.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/e6a98c0d45071c4a46c3fc9e417c009f/wawaxuligesax.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/31581698436.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/6da4066394c9d283e68509db1ee5557c/sobulawerivejidugazutimi.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/dimob.pdfIn PDF document text
    • https://dgaspcsm.ro/ckfinder/userfiles/files/6143101532.pdfIn PDF document text
    • http://somersetcountybar.org/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50810664779.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/15372816718.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/41337967069.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/pepufizudaputuxarogul.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/69766647632.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/da1f4310e24468dd3f403a740c349521/golasub.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/11ad703d3dab65963ee6aac79cbbf1e7/jidirul.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/58329342180.pdfIn PDF document text
    • http://cutskytools.com/d/files/sulivukefipi.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7e0234864---70085774753.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/vewenunepojajexuxipufox.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/2105212352156460399g3ffc.pdfIn PDF document text
    • http://85560891.com/upfolder/e/files/20210829184509.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bdd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDD3 16672 bytes
SHA-256: d88f6dea8f723b16547b88fea6926e7b80f3fd2f34581e0020e3a053f9ff437e
font_01_sfnt_off0000e8f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001010b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1010B 11320 bytes
SHA-256: ee8bcd349be7960ca399ee64de5b2194dcc8eafab64d5e06db85e546ef319252