Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4e825cea6cf57bc…

MALICIOUS

PDF

84.6 KB Created: 2021-03-29 22:33:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 91eb0cde1ec046f2119a2f5f38f66174 SHA-1: 193bb03b652a71d8dd3e90091e0000b6585ee9d5 SHA-256: e4e825cea6cf57bcda8f71fddd19d1981cbdad649401386c711d3cf320f459de
126 Risk Score

Malware Insights

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

The PDF document contains multiple embedded URLs, many of which are hosted on disposable domains and are part of a link farm, indicating a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to phishing sites or download further malware. The document body, though heavily obfuscated, contains references to 'zoom issues' and 'wkhtmltopdf', suggesting a lure to trick users into clicking malicious links.

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
  • 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://nipisod.ru/strik?utm_term=how+to+fix+zoom+issues
    • https://cdn-cms.f-static.net/uploads/4448116/normal_605aba8726648.pdf
    • http://kitukotobov.medianewsonline.com/36159179086.pdf
    • https://static.s123-cdn-static.com/uploads/4497079/normal_5ff7e412d802f.pdf
    • https://cdn-cms.f-static.net/uploads/4378382/normal_605fc08fc2f8d.pdf
    • http://myimperfectmomlife.com/iceberg_slim_pimpthbc0.pdf
    • http://casser.xyz/ir_extender_for_cable_box_best_buyyi7x4.pdf
    • https://static.s123-cdn-static.com/uploads/4393925/normal_5ffb467e65a22.pdf
    • https://cdn.sqhk.co/riragimi/ruu3giK/56377417389.pdf
    • https://static.s123-cdn-static.com/uploads/4484143/normal_5fe37f7dc6623.pdf
    • https://cdn.sqhk.co/matijamaj/jahaqic/sdge_billing_phone_number.pdf
    • https://cdn.sqhk.co/womelage/fT1KLvR/the_real_real_housewives_of_new_york.pdf
    • https://cdn.sqhk.co/tisojubew/X8NZheH/2213425247.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://e40da922-b0e4-44be-9878-2d4898ccab21.filesusr.com/ugd/3a38e0_87812128ec4e4de09105c755fd038060.pdf?index=true
    • https://s3.amazonaws.com/leteraxewe/19830769276.pdf
    • https://s3.amazonaws.com/vawoginele/zubaraput.pdf
    • https://87b84290-c0b3-4c73-97a1-3d59c64c3f69.filesusr.com/ugd/c638b7_61e9afadac8347238dedbe3f0a8bf07f.pdf?index=true
    • https://s3.amazonaws.com/xetasif/45924620997.pdf
    • http://rususekobijo.myartsonline.com/delonghi_pinguino_4_in_1_portable_air_conditioner_14000_btu.pdf
    • https://8767aa75-4bd5-48c0-94ca-24e983238001.filesusr.com/ugd/debdc1_52402dd7f349442da2e049e0368c4ab7.pdf?index=true
    • https://9e1bd277-069e-4713-bdcc-1ab96cf790c3.filesusr.com/ugd/5fd2af_e6d49e2d7477447da16f65f169a22889.pdf?index=true
    • https://4b002d3c-a55f-42ce-816c-238f848e88a9.filesusr.com/ugd/3398cc_cca8ba0e0c3a4f87b3f2459a5659fd2d.pdf?index=true
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010fc6.bin
1ab2f48ab0014a3073f287d5d28d9d3fc480a71e2b5c6403206e308ebcc549b5
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FC6 4748 bytes
font_01_sfnt_off00011ffb.bin
c68b7d316857d5a22b252e32123f3de2d2cd8fecbb371b9ad308c2fcd9ab2e68
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FFB 11036 bytes