Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1da421dd33fa18b…

MALICIOUS

PDF

88.8 KB Created: 2021-09-04 02:32:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: eb1781bff814e85c107e2e7a2b604990 SHA-1: 4b60b6890aed5977fa61bb8d5519c916de02c66b SHA-256: a1da421dd33fa18b87bab9aa212e870b9a84876c72087f38dd556848e260c229
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a link farm pointing to numerous PDF files hosted on compromised WordPress sites, suggesting an attempt to distribute further malicious content or conduct phishing operations. No scripts were extracted, but the presence of external links indicates a potential for downloading second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://infrive.ru/uplcv?utm_term=gustar+with+infinitives+worksheet+answer+key PDF link annotation
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/bd14fae8c6370c9b49c1e496c3ee238c/27203100289.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608d571ea3f11---58387310209.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-7-14/20210714085242440020.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/90915327210.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/bimosevukim.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/lavepaxojixaxuzaxiseril.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/4e9304a3d85184fe8e9a002eef27fd7b/27949259001.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/9776j4gvgmp4go9u42i3t9vtpo/wilukedufofat.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/e8acedf95cf9e6dc7505d4acf39d63a3/karefokoxuno.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/38900053807.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8a87bba73---zexelokobozavebijazeta.pdfIn PDF document text
    • https://ayurvedaemart.com/uploads/file/panokutukudoworaratal.pdfIn PDF document text
    • http://eraucheta.ru/uploads/file/4687081125.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a19b1fb210b---8791923808.pdfIn PDF document text
    • http://ettermanenterprises.com/ckfinder/userfiles/files/lebudiwufixurivebebabo.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/vodemegegasiwofi.pdfIn PDF document text
    • https://genesislighting.net/wp-content/plugins/super-forms/uploads/php/files/b674b7d78ff160a7ce73af30e63ea48a/sipesomifamedeterisiwe.pdfIn PDF document text
    • https://wipaphun.com/UserFiles/File/8791305544.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ab622b4619b---kebozemubot.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ecbe4759eb---88460031076.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/ug5i8jl3gdhfm04pcog9cjtceu/vulowebezama.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/58460125460.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/91451199571.pdfIn PDF document text
    • http://tuvanthanhlapcongty.biz/upload/ck/files/60954196644.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_off0000f167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF167 10764 bytes
SHA-256: ed6dd9cc427f7cfef1f091e80b0a90f97f34c620d2c0ebfcecf74392155dafa2
font_01_sfnt_off00010a45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012257.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12257 19604 bytes
SHA-256: 78a09ee49fc2b7ffe2f194176dd94a6495180e4df8fd27a4ae7261fb69f50f4b