Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4378078312d4ae1…

MALICIOUS

PDF

80.9 KB Created: 2021-09-17 12:38:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: daceae8fe2df4832dbd925d0fd633078 SHA-1: 6161dbf04a448dc0328df0e9e2728020531d63e6 SHA-256: a4378078312d4ae133b874e236ac4dd8e4e5a09c153435fbeb1aadb6bdb06ebc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning model and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. While no scripts were extracted, the presence of numerous embedded URLs, many pointing to PDF files on various domains, suggests a phishing or malware distribution attempt. The `PDF_SEO_DISPOSABLE_LINK_FARM` heuristic strongly supports the conclusion that this document is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://driscollandgibson.com/images/edit_images/file/jizibizewida.pdf In PDF document text
    • http://marymo.ru/uploads/files/54065517069.pdfIn PDF document text
    • http://labsshop.com/d/files/xotulusiri.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/gegubarabajamutalitib.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327307b06b9---xolobaralixolakowusafi.pdfIn PDF document text
    • https://emotionalgift.youngzonejewelry.com/ckfinder/userfiles/files/tujogevusikuwiwijafad.pdfIn PDF document text
    • https://harom.ro/files/file/rukatunevumotuluten.pdfIn PDF document text
    • http://dbexpertise.fr/catalogue_dynamique/file/58332480121.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/9802586727.pdfIn PDF document text
    • https://vroa.pl/chplusfiles/file/lenineditalaniwega.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/newigefiwinirage.pdfIn PDF document text
    • http://artc-polymers.com/upload/images/files/pusowufewetofog.pdfIn PDF document text
    • http://www.cavice.fi/tiedostot/files/19463233571.pdfIn PDF document text
    • http://d2dgroup.net/upload/files/gosowipelikogebo.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/duzib.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109161001407017.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///gimuwi.pdfIn PDF document text
    • http://hykylalumni.org/userfiles/fogonotarapaxujegiduku.pdfIn PDF document text
    • http://clubsahdianagalati.ro/upload/editor/file/95546917832.pdfIn PDF document text
    • http://aweibel.com/Photo/file/misil.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/53441663095.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613180fbd92a3---dewowes.pdfIn PDF document text
    • http://lamgi.pl/ckfinder/userfiles/files/6492212034.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/62042437585.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=install+ubuntu+side+by+side+windows+10PDF 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_off0000d609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD609 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE20 10708 bytes
SHA-256: ab2bb6343c61283786f2e7e19cccf0707cda549d1c5d1dab7d55b1eb2a87e9c8
font_02_sfnt_off000106e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E6 18152 bytes
SHA-256: 093337a2911c3e7fd5b35aba8f193e13a5d327e3039ba869794d520c091bc169