Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a3c25af0a57962…

MALICIOUS

PDF

73.8 KB Created: 2021-04-03 02:54:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 30be4ada5d30706e6467c67ca912b9f0 SHA-1: efd0a8617f50020dd89aa785921fec89ec1f4187 SHA-256: a3a3c25af0a57962218f55e005941f0e34449043487904da493a48da5c2aefd8
184 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics as malicious, including a critical finding for linking to known malicious redirector infrastructure. The embedded URL `https://yafferge.ru/wix?keyword=general+chemistry+lab+manual+answers+pearson` is presented as a lure for educational content, aiming to trick users into clicking it. The ML classifier and ClamAV detection further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/wix?keyword=general+chemistry+lab+manual+answers+pearson In PDF document text
    • http://bugilinupapud.mygamesonline.org/free_arduino_course.pdfIn PDF document text
    • http://miwewumexurigan.sportsontheweb.net/jolafutilosazodarasas.pdfIn PDF document text
    • http://bomepufibawil.scienceontheweb.net/levadob.pdfIn PDF document text
    • http://nujagexurej.medianewsonline.com/sansa_clip_zip_replace_battery.pdfIn PDF document text
    • http://bcpreactiva-enlinea.com/93964846781y2nz0.pdfIn PDF document text
    • http://gidujoluj.mypressonline.com/bank_nifty_books.pdfIn PDF document text
    • http://vinnipoh.fun/dekh_bhidu_caller_tune_jio5qk5o.pdfIn PDF document text
    • http://creditscoretracking.info/lakut85b5o.pdfIn PDF document text
    • http://form-lnstagramverifiedbadges.com/bhai_the_gangster_game_hack_apkcdyyq.pdfIn PDF document text
    • http://storeeuro.info/kiss_the_rain_sheet_pianoa62xi.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/satudifin/poker_hands_cheat_sheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc3c89e5-c4ab-40e3-b3a8-a378e99ed4b3/is_fusion_360_free.pdfIn PDF document text
    • https://5d94d51b-2702-4b64-8df3-eadd022f3edc.filesusr.com/ugd/2ddd39_0591f8bf5ca34abeb2825081279d5a27.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/midizaxopazeji/bc-_fips_jar.pdfIn PDF document text
    • http://xobibaga.myartsonline.com/articulation_sacro_iliaque_anatomie.pdfIn PDF document text
    • http://nafaradevofipaf.myartsonline.com/biblical_hebrew_study_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/061057d7-c9cc-43e6-ab55-ebf692ca5568/vilemejiboxu.pdfIn PDF document text
    • https://2791e1c6-719d-47aa-bdc5-1556df251b63.filesusr.com/ugd/7757c5_a7347cedf16e42c894d2eb16c46dc5e8.pdf?index=trueIn PDF document text
    • https://b4095e1f-5e43-4c35-8b28-ff0c3185c247.filesusr.com/ugd/9cc3de_96a3a8f1032c4cbb970a37b002a79a76.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/remuv/uniform_school_bus_accident_report_form.pdfIn PDF document text
    • https://580b68e3-2104-4118-ae5b-4f285de1c062.filesusr.com/ugd/dad7b5_6de4244fbb0e4d719176fbdb197737e7.pdf?index=trueIn 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_off0000e136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE136 5536 bytes
SHA-256: f4122f0bfdb5a7a5127e5ddc08b98598b08c827681d054d87c4d02d71a6f034b
font_01_sfnt_off0000f3f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F1 11400 bytes
SHA-256: edf97ab22fe3075293114da988932f2f2318d6c2735304933d24a8e604d49d40