Malicious PDF — malware analysis report

Static analysis result for SHA-256 d965f44664d2999d…

MALICIOUS

PDF

73.5 KB Created: 2021-03-30 22:37:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: bf4af2fe372d6cd42e152cfdd9ea2cd4 SHA-1: 508e885f982341be535301b246acb3a1ac616f84 SHA-256: d965f44664d2999df4509fa2e892d3a1fe6526a4158a0e0efe9c87dbdbd30a29
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, indicating it functions as a link farm. Heuristics like 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this purpose, with many links pointing to potentially disposable hosting. The ClamAV detection and ML classifier further confirm its malicious nature, likely related to phishing or SEO abuse.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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-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://jacksth.ru/wix?keyword=vegium+lab+answers
    • https://cdn-cms.f-static.net/uploads/4392457/normal_60608ad2ab59d.pdf
    • http://kalowodopole.mygamesonline.org/7671872060.pdf
    • http://bixaxivajujojar.mypressonline.com/29159838237.pdf
    • https://cdn-cms.f-static.net/uploads/4382773/normal_605c5264d2b30.pdf
    • https://static.s123-cdn-static.com/uploads/4414173/normal_5ffe2fd67eb48.pdf
    • https://cdn.sqhk.co/pepupiribojo/jjayxhr/whipped_frosting_recipe_for_cake_decorating.pdf
    • https://cdn.sqhk.co/vifejoneses/idzBheW/prison_run_and_gun_level_24.pdf
    • https://cdn-cms.f-static.net/uploads/4467003/normal_605adc262e7b0.pdf
    • http://suziterunedoloj.sportsontheweb.net/32538922217.pdf
    • https://static.s123-cdn-static.com/uploads/4471273/normal_5febe0849da36.pdf
    • http://tuzogat.sportsontheweb.net/occupational_health_hazards_of_hospital_staff_nurses.pdf
    • https://cdn-cms.f-static.net/uploads/4480399/normal_603255d745706.pdf
    • https://cdn-cms.f-static.net/uploads/4413235/normal_600e77e7426cf.pdf
    • https://cdn.sqhk.co/mobubivifa/jghaher/.pdf
    • https://static.s123-cdn-static.com/uploads/4413575/normal_5ff1098d530a0.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://dc383e6d-b7a3-4e67-a88a-227fa542b6c3.filesusr.com/ugd/72b0e7_666bc267537f4c0992e556ae80c8200e.pdf?index=true
    • https://65d0a56f-4074-4e8f-9acc-29e6f8e8f663.filesusr.com/ugd/37655d_22a8ad20e05d44c3ae006e3a50f5b9e2.pdf?index=true
    • https://2acf176d-1645-44e4-83be-c67f7ac9af6b.filesusr.com/ugd/e72dd6_63ffbcd2d5684e93be255d36442399c9.pdf?index=true
    • http://zisukuvi.atwebpages.com/stephen_king_movies_and_shows_on_hulu.pdf
    • https://c4647614-9ff8-4b00-b819-08dc938bd166.filesusr.com/ugd/5d3f24_22ec287899c24350853f39bd5d9c029c.pdf?index=true
    • https://87b84290-c0b3-4c73-97a1-3d59c64c3f69.filesusr.com/ugd/c638b7_198edd2483854d30858831f50ca8dba9.pdf?index=true
    • https://d85b1738-a471-4043-b59e-116b2bb794a3.filesusr.com/ugd/97927e_1c2148a09c6a49b9a41c750d8b9f6133.pdf?index=true
    • https://6974b9b2-fc2a-4e9b-9495-84ff65489eb7.filesusr.com/ugd/395280_6ed0eab9b5be4f388a0339ccb4b1b66d.pdf?index=true
    • https://0a3c8164-ddd9-4522-8472-457ce31ece15.filesusr.com/ugd/d32f78_880b8d48fed7469394ac996df088edfd.pdf?index=true
    • https://d5fd0048-bb8d-45a1-ba21-28d1cb0b7162.filesusr.com/ugd/5e8de6_31d516b73893430ab02793baebd2c7f4.pdf?index=true
    • https://b7e73dfe-ad35-4791-b4f7-7500f5b7882c.filesusr.com/ugd/bc79a4_dc947794c32940129320bbc778b91e25.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_off0000dded.bin
04ee879c0b20a2e55f7f41372bd8cfca28c58676b3f5829685f187116d6babd7
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDED 5204 bytes
font_01_sfnt_off0000ef9e.bin
418816ccd81559d5682ded242cd1dda5317ceea3b0816e6e09cf264fe4f5a78a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9E 12032 bytes