Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3f92cc6363e4197…

MALICIOUS

PDF

69.6 KB Created: 2021-10-02 13:44:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 8eefa78fd749e82643fbfb3fdb652c7f SHA-1: 64eb44e46c0f72d0262af9f6a10abc70d0a95151 SHA-256: a3f92cc6363e41977a8e5221f383dc2099cebb7b0f35a9a3660236e298badf62
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URIs pointing to disposable domains, suggesting a phishing or scam attempt. While no scripts were explicitly extracted, the PDF format often utilizes JavaScript for malicious actions, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 5

  • 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.
  • 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://detectagsafety.com/ckfinder/userfiles/files/bowaxedugif.pdf In PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/41276007388.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/56329765175.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/xowafisumo.pdfIn PDF document text
    • http://sadrokartonyhk.cz/images/fckfiles/file/givinumuwiferugatim.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/liwenebejatogib.pdfIn PDF document text
    • https://nomortiga.com/contents/files/25355942419.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/56228787651.pdfIn PDF document text
    • http://africalegal.nl/userfiles/file/19728391644.pdfIn PDF document text
    • http://dtjxbpzx.com/filespath/files/20211002000858.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/79156063631.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/731cd7835da786f0ef2b258f96f7c5f6/zamexedixizasesa.pdfIn PDF document text
    • http://gartenmessebau.de/uploads/files/57022785313.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/butatujesomirux.pdfIn PDF document text
    • https://www.agcontraincendios.es/ckfinder/userfiles/files/vojawelujisupunukibu.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/92312906080.pdfIn PDF document text
    • http://ghettaetamionarchitetti.it/userfiles/files/bobetupidabe.pdfIn PDF document text
    • http://arabic.cz/ckfinder/userfiles/files/35490053520.pdfIn PDF document text
    • https://takipbizde.com/calisma2/files/uploads/kuxitutopugakekomom.pdfIn PDF document text
    • http://wawabed.pl/uploads/userfiles/file/72967730966.pdfIn PDF document text
    • https://freebcard.com/ckfinder/userfiles/files/rubilemiperaxikasezubaf.pdfIn PDF document text
    • http://lapempi.nl/ckfinder/userfiles/files/87202356206.pdfIn PDF document text
    • http://kht.civilkozpont.hu/uploads/file/6518454939.pdfIn PDF document text
    • https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/26762645859.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=bf7587+filter+cross+referencePDF 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_off0000af03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC715 15756 bytes
SHA-256: 9117c0b06a4759b0da5c21d6f0cb4bd1850ceef10358cff6f283839f47a0d6fa
font_02_sfnt_off0000eed7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEED7 10612 bytes
SHA-256: e2ba65d5ee2a9c56fc6d66016d8df42a9ad93f3b57ffe61c222095765ed8521d