Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a9941cdecc5fb1…

MALICIOUS

PDF

81.9 KB Created: 2021-02-28 09:09:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: aa0b3e58f56f6c6d8fc7731c1c948fd4 SHA-1: 09eec65a2e44eea3c1cbd81cff97df8cff54f1a7 SHA-256: 81a9941cdecc5fb15a08fb06e0bf78661c3eddd02bce0c502871ac93c640cbe2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document flagged by ClamAV and an ML classifier as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one prominent URL `https://baarspo.ru/aws?utm_term=toyota+camry+se+price+in+nigeria` suggesting a lure related to car prices. The heuristic `PDF_SEO_DISPOSABLE_LINK_FARM` indicates a pattern of using disposable hosting for multiple links, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://baarspo.ru/aws?utm_term=toyota+camry+se+price+in+nigeria PDF link annotation
    • http://temppicture.xyz/ninekuvevoxotorosilkfwh.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417990/normal_5ffe41f9599d8.pdfIn PDF document text
    • http://madusotiju.22web.org/octonauts_creature_report_lion_mane_jellyfish.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381091/normal_602c210a05177.pdfIn PDF document text
    • http://dreamingdeveloper.com/cisco_packet_tracer_commands_cheat_sheets8sec.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4449771/normal_5fc5ed8c00a33.pdfIn PDF document text
    • http://lupuneruw.iblogger.org/install_setuptools_windows_without_pip.pdfIn PDF document text
    • http://kurixuj.sportsontheweb.net/67647610001.pdfIn PDF document text
    • http://anyita.space/how_do_i_add_my_employee_discount_to_my_safeway_carddcove.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465142/normal_5fe54c79485ab.pdfIn PDF document text
    • http://sujabupinoda.scienceontheweb.net/adidas_watches_price.pdfIn PDF document text
    • http://teksalle.xyz/fanesinozuvuwovibee24id.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/zategafozasiru/5147249282.pdfIn PDF document text
    • https://s3.amazonaws.com/kudefem/lavibobejesa.pdfIn PDF document text
    • http://xuvekixofeku.onlinewebshop.net/51534686835.pdfIn PDF document text
    • https://s3.amazonaws.com/likadojivivofu/oh_lord_how_excellent_sheet_music.pdfIn PDF document text
    • http://vumamuv.myartsonline.com/who_was_the_first_ruler_of_mesopotamia.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ffff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFFF 5272 bytes
SHA-256: 6f1420b775089a34ac94a0a7885c28e9b57427da260f96b768fe55283c9abe42
font_01_sfnt_off000111e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E5 12012 bytes
SHA-256: 64ae48b3cf05ef404f2af0fc30285fd88ca1a8d0629515fcfc6d0b218fbd9ce1