Malicious PDF — malware analysis report

Static analysis result for SHA-256 2fb1fa79492a5892…

MALICIOUS

PDF

81.6 KB Created: 2021-10-08 08:34:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 10ce37bea72c3955d6f11d5c347557cd SHA-1: 3b316c8da9df48e40ed0ecc9983c2e1627647ea7 SHA-256: 2fb1fa79492a5892cb54d7dd4ca010983696d00385d04e1c47c597c0d36875f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://archism.ru/uplcv?utm_term=watch+the+photograph+movie+2020 PDF link annotation
    • http://amdind.com/userfiles/file/sobizo.pdfIn PDF document text
    • http://school15-tyumen.ru/f/16728111866.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/tedus.pdfIn PDF document text
    • http://1night2day.com/UserFiles/file/nivareterador.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/44408951636.pdfIn PDF document text
    • https://perfecthospital.org/ckfinder/userfiles/files/92539523287.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/64967523282.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/161501cc256c34---29471226840.pdfIn PDF document text
    • http://myarrahnu.com/mo_images/files/komusas.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138790b5e395---7663197000.pdfIn PDF document text
    • https://electroagro.es/pub/files/ninifuvek.pdfIn PDF document text
    • https://limsurempat.com/contents/files/nonek.pdfIn PDF document text
    • https://fainitelecommunication.com/public/editorfiles/file/gewonafosowemujulevuxatit.pdfIn PDF document text
    • http://studiopassarotti.it/userfiles/files/55112679340.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/39078306120.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20211001095512.pdfIn PDF document text
    • http://ckud.handysociality.com/upload/files/75290397992.pdfIn PDF document text
    • http://appli-veolia.net/ckfinder/userfiles/files/tuvamurudimebuvapefesux.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/64674589667.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/d73rbq7oclb2dcu6s8uk38h8iu/sijitujazor.pdfIn PDF document text
    • http://gld-lining.com/user_img/files/zojigatosopimagawodex.pdfIn PDF document text
    • http://pentas.eu/userfiles/file/jazedadegemotava.pdfIn PDF document text
    • http://nakloboucku.cz/uploaded/file/18610951444.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/fokonivawesilujixetog.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_off0000d79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD79E 18444 bytes
SHA-256: 1dc4136ac048a4f43621570705b2979f30e7c8dc027fa3960f8076f67e4e8835
font_01_sfnt_off0001075e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F75 10804 bytes
SHA-256: 9c0a3733c4c729dcb8fc2f3dfdcba059302de35c0de48b819a213adc51ce8145