Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa58b427ddc1051…

MALICIOUS

PDF

92.8 KB Created: 2021-02-14 11:25:31 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 245c20f0d198c4c525879550dc3d9f56 SHA-1: defd0276752cd3ff57b9853f701545f93bf23ca4 SHA-256: caa58b427ddc1051b8c36fb2dfee74f242b477c22af99e377a16b7976251cb0c
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. The embedded URLs and the nature of the heuristics point towards a malicious PDF designed to lure users to external, potentially harmful, 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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/123?utm_term=how+many+different+types+of+bones+are+there PDF link annotation
    • https://parafobosa.weebly.com/uploads/1/3/1/8/131857791/b8dba0.pdfIn PDF document text
    • https://cdn.sqhk.co/geruxibab/hk2IpjF/tastiest_blueberry_muffins.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491445/normal_601b627ce35f5.pdfIn PDF document text
    • https://cdn.sqhk.co/kewixoretuze/f4Shgjj/audio_equalizer_app_ios.pdfIn PDF document text
    • https://cdn.sqhk.co/padixemugex/nia8jig/texas_longhorns_women_s_basketball_schedule_2018-_19.pdfIn PDF document text
    • https://kokubexajaluk.weebly.com/uploads/1/3/2/6/132681668/kejilusesasuwom.pdfIn PDF document text
    • https://nawexolaka.weebly.com/uploads/1/3/4/7/134704757/4050974.pdfIn PDF document text
    • https://cdn.sqhk.co/vomawoko/gqhg2bR/gibetuxolabogede.pdfIn PDF document text
    • http://wozutujetotox.iblogger.org/formative_assessment_maths_class_10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498834/normal_5fd81c4955ac5.pdfIn PDF document text
    • https://cdn.sqhk.co/pofadugilip/hfDHxAF/38208090654.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • http://nivutegem.epizy.com/sikipanaxojutuked.pdfIn PDF document text
    • http://lixanixuzuki.rf.gd/anbe_peranbe_video_song_isaimini.pdfIn PDF document text
    • http://durunorutap.epizy.com/rupinder_gandhi_real_images.pdfIn PDF document text
    • http://bibesatu.epizy.com/fanupubiroximopojigas.pdfIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBDE 5332 bytes
SHA-256: 8b13a5b616201f1ada08e039a356ad096b2576bb7f03be5a20f36cf5fc60b5fa
font_01_sfnt_off00010dd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DD4 10952 bytes
SHA-256: 6169b4b9b5d5603b25d07adc2599b745137f1207359fb9e0b385fabe915d1c2b
font_02_sfnt_off0001336c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1336C 16152 bytes
SHA-256: b4a1327a55bc8a8c15df99472a79f6c7d6bf064e5452bf43ebbdc05fa9d13721
font_03_sfnt_off00014877.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14877 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
font_04_sfnt_off00015677.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15677 3604 bytes
SHA-256: f9fe22d545712eedfaf623189131faddc99eb22626534d4abc9b0b50efa89f73