Malicious PDF — malware analysis report

Static analysis result for SHA-256 df1b9196275e98e9…

MALICIOUS

PDF

71.7 KB Created: 2021-09-18 07:04:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 546167d908d94d0420689f9df4b1a497 SHA-1: a4ba07f9adf161046893f13d8cd53b4075e43072 SHA-256: df1b9196275e98e981ce52aafb269c355621f74f136e2c18d46d8e51ff034029
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The presence of numerous external URIs, many pointing to PDF files on potentially disposable domains, suggests a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to download and execute a second-stage payload or redirect the user to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://anhuizhkj.com/upload_fck/file/2021-9-11/20210911211558215608.pdf In PDF document text
    • https://luiginoiobbi.com/userfiles/file/7947471815.pdfIn PDF document text
    • http://khachsanmyngoc.com/upload/files/kigebimexaker.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/18578548132.pdfIn PDF document text
    • http://dotykbylinky.sk/_subory/subory/lepaziriwapamobimagapifep.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/92309763153.pdfIn PDF document text
    • http://pyramidplaster.com/file_media/file_image/file/rasajajozeredisezav.pdfIn PDF document text
    • http://studioprogettoarchitettura.eu/userfiles/files/66758220176.pdfIn PDF document text
    • http://handinks.com/ckfinder/images_store/files/17199010018.pdfIn PDF document text
    • http://thomas-zigon.de/images/file/33542812726.pdfIn PDF document text
    • http://usairsprings.com/userfiles/file/boxovabavavik.pdfIn PDF document text
    • https://beautydent.hu/editor_up/luvixidevepuve.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/jufitodumoruduvemekelel.pdfIn PDF document text
    • https://newchat.xyz/js/ckfinder/userfiles/files/gipilebuxarovimixi.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/69406324347.pdfIn PDF document text
    • https://www.corpeverest.com/ckfinder/userfiles/files/50852451767.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/97891690678.pdfIn PDF document text
    • https://cissud.it/uploads/ck_editor/files/42660104957.pdfIn PDF document text
    • https://smobiil.eu/userfiles/files/42639964453.pdfIn PDF document text
    • https://38e5bbdfe8be.gdziezjesc.info/userfiles/file/18830774509.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/ruxerapiliponoruvu.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/49990032192.pdfIn PDF document text
    • http://kkagro.com/media/images/upload/file/48106987274.pdfIn PDF document text
    • http://avatars.ru/userfiles/file/tavejinelekobanadotu.pdfIn PDF document text
    • https://spandoekland.nl/userfiles/file/81796670768.pdfIn PDF document text
    • http://hladonural.ru/upload_picture/supusurenu.pdfIn PDF document text
    • http://abc-tel.ru/data/File/89769071636.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613131f488840---1221155879.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=learn+english+with+jennifer+lesson+5PDF 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_off0000b8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C2 15276 bytes
SHA-256: 27aa13df4729e21a70418f1747c1878fe1868f4c7af1d335f7af6509e9146ecd
font_01_sfnt_off0000dff8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f80f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80F 10800 bytes
SHA-256: a11d82c1771eff8866e9fea20b3702ebea20bf56c9ce3c8359f1997af28464e3