Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3f556726bf52669…

MALICIOUS

PDF

90.1 KB Created: 2021-08-15 07:46:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8829831cea74a832bd7e6e9d098c8e10 SHA-1: 2682fbea583e9e51e4d28bdfb9762f7baaca2716 SHA-256: a3f556726bf52669a3fa78286ae11cb630b4598c51d758f989d70f038e521c7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL analysis point towards a malicious PDF designed to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://yukkumpulgroup1.com/contents//files/lafaxamevi.pdf In PDF document text
    • http://tks-forever.com/upload/2021/06/24/file/63415488244.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096a7ec69f43---saliwovulesoba.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/7476fe9e0f50b92cbf506179c1921864/bekiwuradod.pdfIn PDF document text
    • http://peak-experience-europe.com/images/blog//file/bilitukedibunorut.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/a42191a95eef1ef3a710127e35603d55/sifigexajizoxutomofagukal.pdfIn PDF document text
    • http://irishvaughans.com/clients/7/7c/7cfe0b8ff6d5e3136a6575a9b258a09c/File/85240498836.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/6008588506.pdfIn PDF document text
    • https://sunnyrosesschool.com/userfiles/file/1888783049.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb732a5ba4---99411013985.pdfIn PDF document text
    • https://congchung7.com/upload/file/rivato.pdfIn PDF document text
    • http://mueblesdepladur.es/1/userfiles/file/51376136728.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/suridixurerapumato.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161154a874223a.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/5402235893.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a812fce87f4---22488443329.pdfIn PDF document text
    • http://rudolphalexander.com/uploads/files/70575510883.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/jivefububu.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55144779268.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16117ee3d3f7cb---36474965155.pdfIn PDF document text
    • http://vejwun.cz/images/84506750470.pdfIn PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/tuvuveketelotite.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/89a14b92a120530baab2bdfb2c2c5949/dimufosukijofobadomawow.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bc8a5077600---gelikan.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/0ib0f47hfn6g2p3bq3v7lil5pa/rejufimotevajelipibuvobaj.pdfIn PDF document text
    • https://drsubhashawale.com/ckfinder/userfiles/files/68500176271.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=android+version+names+a+to+z+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://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_off0000f8aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8AA 10720 bytes
SHA-256: 26ff7370c0af17f4fde0e9f56fc22906c0a6148003428499632504697971c323
font_01_sfnt_off0001115b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1115B 18488 bytes
SHA-256: c014f1d9384a942c8a5a029d3cf5128da412b5b3825cd880427e491631330603
font_02_sfnt_off00014160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14160 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1