Malicious PDF — malware analysis report

Static analysis result for SHA-256 e735099be177bb75…

MALICIOUS

PDF

79.5 KB Created: 2021-09-18 08:27:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 93ae7e59437691435a76550998eb799a SHA-1: 2e9bddc65230d27f1358374750aa05158f4e73ce SHA-256: e735099be177bb7587ef18af68be24c913ac441349f0210eb0721ccf295e4021
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning model indicated a high probability of maliciousness. Heuristics indicate the document functions as a link farm, hosting numerous links to other PDF files on various websites, some of which appear to be compromised. The presence of multiple unknown PDF URLs suggests a campaign to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://mitrasuksesku.com/userfiles/file/zugokewezezubexopifuvapo.pdf In PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/21892154578.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/29595768006.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/369f221ccdff22792a0e712e9c1d4be7/97209325405.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/1343810520.pdfIn PDF document text
    • https://halkum.rs/files/sogutulegebipu.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/57822742332.pdfIn PDF document text
    • http://www.civilhospitalpalampur.in/img/uploads/files/kafusumefoxanowurogasaz.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/33365289411.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/xazobepomegafimewil.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/42408631735.pdfIn PDF document text
    • http://wenxuezj.com/images/File/76351995645.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c212bc8702---25523433566.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161336a90169bd---4269770581.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/55934177895.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/66994204509.pdfIn PDF document text
    • https://computerzone.pk/file/35398851853.pdfIn PDF document text
    • http://zubrcup.by/files/files/99741120360.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfcd466946---wokipifapebaxasixuw.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/29613162892.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=chawal+house+web+series+online+watchPDF 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_off0000d3f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F5 10684 bytes
SHA-256: 0079631a7c614b6883e7133f94a39df59bcb49a38fdd8f8ae46f514a25dc8bec
font_01_sfnt_off0000ec84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC84 16872 bytes
SHA-256: ce04b3de6016e10d6fe3d4ff3dff10b2adbdf2027ae46049b331027382527954
font_02_sfnt_off00011878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11878 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1