Malicious PDF — malware analysis report

Static analysis result for SHA-256 21613ab53ce09d6a…

MALICIOUS

PDF

79.2 KB Created: 2021-04-27 04:51:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 5ad2616f626c4b737233fc1f2046357f SHA-1: c35e63ffac8cd5ae8d08a6ffe74a318b09641eab SHA-256: 21613ab53ce09d6a3fd40bad78b5971f2ef104e571f1a2f7f588812d4b07859c
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the sheer volume of outbound links points to a coordinated effort to direct users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://nipisod.ru/strik?utm_term=interactive+grammar+exercises+for+esl+students PDF link annotation
    • http://xuxetosufuzo.getenjoyment.net/action_research_sample_in_science.pdfIn PDF document text
    • http://iwhite.space/64485828818chshn.pdfIn PDF document text
    • https://dodarumobite.weebly.com/uploads/1/3/1/4/131437296/voxiwuzapejiwe.pdfIn PDF document text
    • http://robinmani.site/jewoverulefevotidwmpd.pdfIn PDF document text
    • http://dragonflysagewellness.com/rafazakuss9p1j.pdfIn PDF document text
    • https://lorumotavur.weebly.com/uploads/1/3/4/6/134693112/7798716.pdfIn PDF document text
    • http://reactivascotia2020.com/can_you_use_playstation_3_remote_on_ps48dsc2.pdfIn PDF document text
    • http://lakuberik.mywebcommunity.org/todibegotivotufefatakel.pdfIn PDF document text
    • https://zidivopopa.weebly.com/uploads/1/3/4/3/134373798/bozevufunefa.pdfIn PDF document text
    • http://parkji5x.xyz/118528759397vf50.pdfIn PDF document text
    • http://limons.space/36695239017j2frc.pdfIn PDF document text
    • https://bizawipogimiwa.weebly.com/uploads/1/3/4/3/134316434/nejaxitom.pdfIn PDF document text
    • http://euroshopmn.space/online_speaking_english_practice_free_app5xflo.pdfIn PDF document text
    • http://wide-do.top/actualizacion_android_10_xiaomi_mi_a22v7av.pdfIn PDF document text
    • https://nubesojobe.weebly.com/uploads/1/3/1/3/131398221/wukagubomekajul.pdfIn PDF document text
    • https://nuvusutapisi.weebly.com/uploads/1/3/4/4/134460305/muwepipaxonexijoxo.pdfIn PDF document text
    • https://pugulewex.weebly.com/uploads/1/3/1/4/131406013/forozuralow_rigerosakejipin.pdfIn PDF document text
    • https://topudikuwem.weebly.com/uploads/1/3/4/0/134042537/lojudimud.pdfIn PDF document text
    • http://lubenoredeji.mypressonline.com/dosot.pdfIn PDF document text
    • http://good-production17.site/duweterirupiloz3gazi.pdfIn PDF document text
    • https://sozaruterir.weebly.com/uploads/1/3/0/7/130738534/vipuwejagebefaf.pdfIn PDF document text
    • http://niwadeg.mywebcommunity.org/22734128129.pdfIn PDF document text
    • https://lemevepavakupe.weebly.com/uploads/1/3/4/7/134701524/c0cdad0a9fef.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ad9e3d1f-bb22-46ca-892e-b6aa3325a756.filesusr.com/ugd/837d34_b8aeb64b7ea64e00b96c840f9a2af0d4.pdf?index=trueIn PDF document text
    • https://ebc1add8-0b9d-418e-9e4a-1e287827e933.filesusr.com/ugd/ab63e3_0375d89f9cf64f1abc0dcb2589643014.pdf?index=trueIn PDF document text
    • http://memamawu.onlinewebshop.net/fapopilem.pdfIn PDF document text
    • https://625f08e2-3d8e-45b5-8e8c-b95d001c5c7c.filesusr.com/ugd/d94ae5_d1e527f9470d4ca891827501505c7f8d.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f635.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF635 5404 bytes
SHA-256: 97a82975923cce8eb99d230370ae31d83fbf536f7e61ed3114cc75dae19d2978
font_01_sfnt_off0001088b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088B 11184 bytes
SHA-256: 9b5a1644c1841ffad89d188b683dfdd43691e97b3c8fa44690d6abec758f9ca8