Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91f8bfbbe296357…

MALICIOUS

PDF

80.7 KB Created: 2021-03-30 00:17:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 2d325a75ded32f0b1a143aeb3811464b SHA-1: 6898b17e6e0191993f7093e33830b30bfbac40b8 SHA-256: c91f8bfbbe2963577555c3f463d0be93041eb1e223326d6e0784866e7e0f231b
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm on disposable hosting. The embedded URLs, such as 'https://xajibur.ru/award?keyword=back+strain+stretches+pdf', suggest a phishing or malware distribution attempt by luring users to external sites. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious documents designed to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://xajibur.ru/award?keyword=back+strain+stretches+pdf PDF link annotation
    • https://cdn.sqhk.co/baruduwege/ZjfhfPs/c_check_compiler_version.pdfIn PDF document text
    • http://persequen.com/79873695546ai9gu.pdfIn PDF document text
    • http://dazavaluk.mygamesonline.org/44922908460.pdfIn PDF document text
    • http://wovugikanagak.scienceontheweb.net/raxezigopalafugivi.pdfIn PDF document text
    • http://sevowina.medianewsonline.com/hot_springs_spa_heater_not_working.pdfIn PDF document text
    • https://cdn.sqhk.co/nebuwaxisiw/hjhgijK/dragon_hills_2_mod_apk_android_1.pdfIn PDF document text
    • http://rocketdocs.us/creator_of_mathwayi3baa.pdfIn PDF document text
    • https://cdn.sqhk.co/xobanozizesa/idogicf/glowing_live_wallpaper_cave.pdfIn PDF document text
    • http://changepass.online/6738958753564iwf.pdfIn PDF document text
    • http://sarupunojupud.sportsontheweb.net/gelizawoz.pdfIn PDF document text
    • http://libutulidux.medianewsonline.com/introduction_to_business_management_study_guide.pdfIn PDF document text
    • http://winoorama.website/430147010461xe41.pdfIn PDF document text
    • https://cdn.sqhk.co/pelebitebi/gge38id/colors_of_the_wind_karaoke_piano.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
    • https://s3.amazonaws.com/dedinavesute/heart_of_the_matter_lyrics_india_arie.pdfIn PDF document text
    • https://6f847715-c85a-45d9-ae5c-7c68cc800588.filesusr.com/ugd/6e100b_71839c4250734b34a667ade7cfdf8681.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tiduro/adobe_photoshop_cs5_crack_mac_os_x.pdfIn PDF document text
    • https://s3.amazonaws.com/meludav/50256134210.pdfIn PDF document text
    • https://s3.amazonaws.com/vebenok/55534406084.pdfIn PDF document text
    • https://206c1dc7-391c-4b20-ac64-b63c97020fd4.filesusr.com/ugd/87773f_0ec7cc9e9ece41c2bc11416d4da7b5d1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tujeviwakirawu/nedodavimogi.pdfIn PDF document text
    • http://guxejusoselota.myartsonline.com/53462075424.pdfIn PDF document text
    • https://5d94d51b-2702-4b64-8df3-eadd022f3edc.filesusr.com/ugd/2ddd39_d0af1f1b561343ada3203881cc4b064f.pdf?index=trueIn PDF document text
    • https://9f5bcc56-a059-4f00-ae85-604acd6a3d2d.filesusr.com/ugd/ac9354_6324950ad1294c339c8f28fc2f282ff2.pdf?index=trueIn PDF document text
    • https://05790d5e-93e9-4545-bcc4-99c37f081c18.filesusr.com/ugd/bff4d5_7cd0ec296b034c29ad98bdeab8e04723.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF2A 5004 bytes
SHA-256: f5383de4cc1820849f4f24f18eabd2c119e51cc62f06ac8be43d3df2a9c8c366
font_01_sfnt_off00010019.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10019 10916 bytes
SHA-256: 5b57521c89eefb7782dff2d8d4dda10852a637dfbd82634c7eec18d81f0c798b
font_02_sfnt_off00012575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12575 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3