Malicious PDF — malware analysis report

Static analysis result for SHA-256 842735bbf39c6ccd…

MALICIOUS

PDF

85.0 KB Created: 2021-03-24 22:23:23 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 3c1a88b3c18d7594c5c422b7365e46de SHA-1: 1f6af8881e9614c5bfd492bcf55232a83c120fb5 SHA-256: 842735bbf39c6ccdd119495df046e3bcb6cc932fba33096990fa0442b087120b
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://crophysi.ru/wix?keyword=blue+thunder+brass+band PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4393904/normal_5fddf477cb7ea.pdfIn PDF document text
    • https://cdn.sqhk.co/simizekovogi/ncCiaj3/tekebelamujutafuxawamad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420927/normal_60233401abd75.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493550/normal_5fe9dcf9d4081.pdfIn PDF document text
    • https://cdn.sqhk.co/rorajakura/hjfphjV/cyber_hunter_game_size.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481417/normal_604d84754b3f8.pdfIn PDF document text
    • http://maxiteguf.medianewsonline.com/wiruzisotebe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366957/normal_600f7ffc08b12.pdfIn PDF document text
    • https://cdn.sqhk.co/solalokazili/ahcbt0l/train_or_taxi_from_paris_airport.pdfIn PDF document text
    • https://cdn.sqhk.co/xetokive/EFge94h/31564321639.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sajomapujozokux.onlinewebshop.net/incubus_master_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/078e2bd2-d9e8-4445-9e8a-966c0b635314/our_god_is_able_chords.pdfIn PDF document text
    • https://6376acfe-5884-4251-b3d5-19a03c044549.filesusr.com/ugd/de3d83_3318ff856a7c4259a599ae95f1e748f4.pdf?index=trueIn PDF document text
    • https://dc273c12-e125-4738-b2e6-b96bc4bd5eb7.filesusr.com/ugd/c8df25_c550772204f34850b697254659dd5474.pdf?index=trueIn PDF document text
    • https://5db246a0-94da-4013-9f64-c970003367b9.filesusr.com/ugd/ca5179_61684c127eae435382a1365d6e77c900.pdf?index=trueIn PDF document text
    • https://2080fafa-2491-4ac3-8118-a138f33bff34.filesusr.com/ugd/822ecd_38fc8746ae2845fa863506ccf8b15e76.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc69bcba-9d1c-4e74-b766-b5ef7550f3a3/9573946545.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4828a7f3-c8e4-4183-b544-8f18606a3346/monster_the_autobiography_of_an_la_gang_member_chapter_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6e05849-def0-499d-b341-bef68f3cbe9a/68620969446.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_off00011009.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11009 5100 bytes
SHA-256: 5edd280f4b396fc31192fdca63f231fa1036340016f5328b7f2dc6f69c6c097e
font_01_sfnt_off0001214f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1214F 11024 bytes
SHA-256: 0c1ff407e2fbaac07b936a1c5a6ad754c0f8be3dd5027964800bd849b4158526