Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d337bf8c8d54578…

MALICIOUS

PDF

84.6 KB Created: 2021-04-08 19:47:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ab542bfcc73629bd6b71e8ca2dc96d42 SHA-1: 29b4a906a0d45ec8c3dda8656f228fd31da62279 SHA-256: 1d337bf8c8d54578c5e41425bbd71a35e91ea48164e9318e20550cf57470fe8c
186 Risk Score

Malware Insights

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

The PDF document contains numerous external links, identified as a link farm, likely intended to direct users to malicious websites. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically phishing. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to exploit users by redirecting them to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 6

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dafemum.ru/strik?utm_term=que+significa+so%25C3%25B1ar+que+se+caen+los+dientes+y+muelas
    • https://cdn.sqhk.co/pugudanirav/h00iihd/34930670735.pdf
    • https://mavosawiki.weebly.com/uploads/1/3/1/1/131163846/04f30.pdf
    • https://degubazof.weebly.com/uploads/1/3/5/3/135304991/zowogelunuxoj.pdf
    • https://limakeluror.weebly.com/uploads/1/3/4/6/134657352/dironisajuliruf.pdf
    • https://static.s123-cdn-static.com/uploads/4487916/normal_5fcc8d3e9cd42.pdf
    • https://cdn-cms.f-static.net/uploads/4379377/normal_602b2487ea700.pdf
    • https://cdn.sqhk.co/bojodunaluko/dgideXX/appradio_one_hack.pdf
    • https://wesudami.weebly.com/uploads/1/3/4/8/134881188/5d2086e8035bdee.pdf
    • https://faremuxonebaw.weebly.com/uploads/1/3/4/5/134598019/razapabe.pdf
    • https://static.s123-cdn-static.com/uploads/4457563/normal_5fdf4b83cc918.pdf
    • https://cdn.sqhk.co/midipumep/bhedeie/space_simulator_free_ios.pdf
    • https://cdn-cms.f-static.net/uploads/4412408/normal_605b1c126b64f.pdf
    • https://cdn-cms.f-static.net/uploads/4389599/normal_6017992d43570.pdf
    • https://cdn-cms.f-static.net/uploads/4388406/normal_6023d42865ceb.pdf
    • https://pumijisiror.weebly.com/uploads/1/3/1/3/131381241/2d41e.pdf
    • https://cdn.sqhk.co/dojerilu/gjU0Fib/mini_golf_lancaster_pa_rt_30.pdf
    • https://redirusoko.weebly.com/uploads/1/3/4/7/134704710/kevisijubere.pdf
    • https://static.s123-cdn-static.com/uploads/4411511/normal_5feb7e051fdb3.pdf
    • https://static.s123-cdn-static.com/uploads/4388163/normal_60072a3128b1d.pdf
    • https://rakovarirol.weebly.com/uploads/1/3/4/4/134458111/5031541.pdf
    • https://cdn.sqhk.co/roretuduva/rgdjcij/xetigixutinujidi.pdf
    • https://buxijoxusezo.weebly.com/uploads/1/3/1/4/131483018/7399637.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://ca7c05ed-d233-4774-9cf9-08ff86aa6c73.filesusr.com/ugd/b42fd6_8851e47383d6471d83e60ac6c2f88afa.pdf?index=true
    • https://3d3b31fc-6152-41c7-b1d4-a4af3afcce63.filesusr.com/ugd/3f8d85_380ef4b4685a46e19c7d9a6402da7e59.pdf?index=true
    • https://2b01876c-5741-4e94-bfb6-30973e4a6517.filesusr.com/ugd/45d688_8c97a31e33774d1f87b2eb7076f84cea.pdf?index=true
    • https://291e86d0-b4b7-455e-aeca-30cd05102b29.filesusr.com/ugd/384a46_076c19a7d34d4ea381559daf66031af9.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa72.bin
31fd50f05cbac81dca56c9767ca546b7a8f67b697e6e6512f94c0ed24aa4a98d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA72 5724 bytes
font_01_sfnt_off00010d93.bin
990ebed61fa516f11280a9477f8a46a9ae73b35ec7fa9e5b992da1ec59512da4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D93 11644 bytes
font_02_sfnt_off0001337e.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1337E 4324 bytes