Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9ff0be7a243c189…

MALICIOUS

PDF

77.8 KB Created: 2021-03-29 18:22:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 60bcffc180b72bb6363a8175fcd51c10 SHA-1: 62c060ca023bdd1c40616d41e165172e3b4ee19f SHA-256: b9ff0be7a243c189ac92a5a727b13ce6c438cc819c715b130b0f823aa5ffe3a1
186 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many pointing to disposable domains and link farms, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains metadata related to 'wkhtmltopdf' and a date, suggesting it was generated programmatically to appear as a search result for an academic book, likely to trick users into clicking malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://baarspo.ru/wix?keyword=essentials+of+world+regional+geography+3rd+edition+pdf PDF link annotation
    • https://cdn.sqhk.co/vibisidumes/igtYPje/96233738492.pdfIn PDF document text
    • https://cdn.sqhk.co/zupuguvawaj/djbidib/victorinox_inox_diver_watch_review.pdfIn PDF document text
    • https://cdn.sqhk.co/moxibusas/jf9ghic/dragon_warrior_monsters_3.pdfIn PDF document text
    • http://xonesasa.iblogger.org/pixabexijopewej.pdfIn PDF document text
    • http://vivezotutune.iblogger.org/rincian_apbn_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/nozesinipi/Z5ThiNP/57264126441.pdfIn PDF document text
    • https://cdn.sqhk.co/bimepefav/Jibiaid/free_country_music_ringtones_for_iphone_11.pdfIn PDF document text
    • https://cdn.sqhk.co/wemavutulow/jg3JCVL/21363416421.pdfIn PDF document text
    • https://cdn.sqhk.co/vinasujitupe/eVk2hjI/lefuviduvozeral.pdfIn PDF document text
    • https://cdn.sqhk.co/lomekojop/hj7iegg/my_little_talking_princess_promenade_characters.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nimimetebevazi.rf.gd/63329803230.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dff2fab7-09d5-4824-8607-9f7df4c653a8/last_child_in_the_woods_ap_lang_analysis.pdfIn PDF document text
    • http://kedekivotizera.epizy.com/rogujawizipokisesorum.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b0915e34-ae10-454a-96d4-a34a6431ef6c/my_name_sandra_cisneros.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3fd7a201-3486-4249-8c90-43d1b2db14d3/who_makes_huskee_snow_blowers.pdfIn PDF document text
    • http://rilimopukalus.rf.gd/dunkin_donuts_bavarian_creme_donut_calories.pdfIn PDF document text
    • https://63aa7d51-6c54-48cc-ac87-b710a0da19c3.filesusr.com/ugd/c8d394_577eda19089144bd92fe2329a085d266.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e9545b37-a134-490b-b90e-93555b80df56/echo_pas_225_trimmer_line_replacement.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1f6eda84-2560-407e-8a25-6dcdf3efeee7/first_grade_math_curriculum_free.pdfIn PDF document text
    • https://ad177677-9664-42cd-9bf2-17a10eef6e1d.filesusr.com/ugd/f8915e_8e2274d1b0a744b98ce0b9d3b40a7530.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/075034a3-aaae-4774-9e10-94b02b07ed51/95713085567.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/50600a01-1a4c-4b1b-8821-3527ad14ed6e/xevajijurumejipubowinemu.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_off0000efb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB3 5620 bytes
SHA-256: 5a3a4f04ddfd47718af24aac3bac2280130afa9dae9546b513f773e8e9aea374
font_01_sfnt_off000102ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102ED 11200 bytes
SHA-256: 2ef581764eeb9ff2d5c2bfaa5252ff1404b9c114ee4345e6d8b5c343dedb615e