Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a70f0b3f19a4c6f…

MALICIOUS

PDF

86.0 KB Created: 2021-02-28 21:22:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 64fa12a1d5ca2e6561eb0cb4651d368e SHA-1: a7adc329ad4202cf848f19565b4717c87bcae00e SHA-256: 0a70f0b3f19a4c6f2e295bdcfb9b2e2b993fb9b86b7efb55df902976368686ee
126 Risk Score

Malware Insights

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

The PDF contains multiple embedded URLs, with one specifically pointing to a domain designed to appear as a search result for 'worksheet solving exponential and logarithmic equations'. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were extracted, the presence of numerous external links and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest the document is part of a link farm designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • 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/wix?keyword=worksheet+solving+exponential+and+logarithmic+equations PDF link annotation
    • https://cdn.sqhk.co/tabuguran/jijffgg/wallpaper_hd_for_mobile_free_download_girl.pdfIn PDF document text
    • https://cdn.sqhk.co/barugogip/YhbhgdM/amazon_seller_support_associate_chennai.pdfIn PDF document text
    • https://cdn.sqhk.co/modajili/dij60ge/download_house_flipper_home_design_renovation_games_apk.pdfIn PDF document text
    • https://cdn.sqhk.co/jojikoxazew/hfiidYF/51901225005.pdfIn PDF document text
    • http://gexomafe.mypressonline.com/vizio_sb3820-c6_38-inch_2.0_channel_soundbar_review.pdfIn PDF document text
    • http://navevukosuso.mypressonline.com/xajasipemibololupubureliv.pdfIn PDF document text
    • http://dkmz3.club/weruvarirevuwukaroteli6o7l6.pdfIn PDF document text
    • http://bosemefawixuwov.mypressonline.com/letijapulo.pdfIn PDF document text
    • https://cdn.sqhk.co/bopelara/igjKSje/funny_videos_failarmy_2018.pdfIn PDF document text
    • http://yognat.space/why_is_my_whirlpool_gold_refrigerator_leaking_waterl1sup.pdfIn PDF document text
    • http://sanatoriy-izumrudny.ru/math_transformations_worksheets_8th_grade7k1n0.pdfIn PDF document text
    • http://vaxiliwu.medianewsonline.com/boviwokiratake.pdfIn PDF document text
    • https://cdn.sqhk.co/bewewojiwo/gCMjhhb/xidasime.pdfIn PDF document text
    • http://boost-store.net/shipwrecked_kauai_instagram3f9v2.pdfIn PDF document text
    • https://cdn.sqhk.co/ninivaxibab/heNjfhj/65283856041.pdfIn PDF document text
    • https://cdn.sqhk.co/xexisini/ifuoFH3/subokosemu.pdfIn PDF document text
    • http://tokexal.medianewsonline.com/56588992090.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://tiwosutodegadax.onlinewebshop.net/69230347320.pdfIn PDF document text
    • http://novogizeboje.myartsonline.com/tetuxira.pdfIn PDF document text
    • http://nukilaba.myartsonline.com/how_much_does_ms_project_cost.pdfIn PDF document text
    • http://rivenoke.onlinewebshop.net/rewivolijejitebudinumoga.pdfIn PDF document text
    • http://xiwozoget.atwebpages.com/how_to_analyze_an_advertisement.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD0 5700 bytes
SHA-256: fcd18787781f9835958bd2d380f439dcd31d8391d6410b2c678c05599e75bf7e
font_01_sfnt_off00010315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10315 10272 bytes
SHA-256: 39d76c63b4204b358e135083f9d35182d6a6de62aed727824ff9b476175c4a25
font_02_sfnt_off0001266a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1266A 16096 bytes
SHA-256: 61761e6c71fdd980502ce8a3a8cbf9590216241eb9eabe72fdf309a1c23cd3c2
font_03_sfnt_off00013b33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B33 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e