Malicious PDF — malware analysis report

Static analysis result for SHA-256 c35dc8c5c86508da…

MALICIOUS

PDF

78.0 KB Created: 2021-03-14 05:27:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 3251b198da0516080b44504522b1f814 SHA-1: dee14fd304d7fcdaa70c6b02374bef9046237c39 SHA-256: c35dc8c5c86508da32db8e80313b8110ec8839235e2df9034452c2ddc1aef7f9
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous external links, with one prominent URL pointing to 'nipisod.ru'. The heuristic 'PDF_SEO_LINK_FARM' suggests a deliberate attempt to create a large number of links, likely for SEO manipulation or to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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/wix?keyword=word+whizzle+answers+musical+instruments PDF link annotation
    • https://cdn.sqhk.co/xiwapusumoge/hfZjg23/kiloblocks_lite_full_version.pdfIn PDF document text
    • https://gixujadimi.weebly.com/uploads/1/3/4/7/134708567/a91f44101.pdfIn PDF document text
    • https://vifapuxup.weebly.com/uploads/1/3/4/0/134018045/4827478.pdfIn PDF document text
    • https://wanalupegekiful.weebly.com/uploads/1/3/4/8/134879682/75c02757476.pdfIn PDF document text
    • https://vegebawijinewer.weebly.com/uploads/1/3/2/7/132740558/xugaj.pdfIn PDF document text
    • https://fodumalape.weebly.com/uploads/1/3/2/6/132695584/6777325.pdfIn PDF document text
    • https://jekodijup.weebly.com/uploads/1/3/4/4/134490718/a59b9c8d.pdfIn PDF document text
    • https://lonamejekewow.weebly.com/uploads/1/3/5/3/135396766/9445296.pdfIn PDF document text
    • https://wefupavoxed.weebly.com/uploads/1/3/2/6/132682659/nevivoti-lodifemotavup-kemojusesafel-kabijinudenu.pdfIn PDF document text
    • https://cdn.sqhk.co/nutewakizi/devjaZY/21171662246.pdfIn PDF document text
    • https://pikiromubivi.weebly.com/uploads/1/3/0/7/130739210/werowetunitusin-tizolosigigoro-xinejegizu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d670dda7-df53-4ef1-8eda-d3256df28744.filesusr.com/ugd/dbbbec_dbd3cdf1eae84cb2b2963d90e0e556c5.pdf?index=trueIn PDF document text
    • https://0c3b2bb2-3ac9-4e0e-a0b2-530a831cdf0d.filesusr.com/ugd/23193f_1f88907094444f3dba4f73ccbf2565d9.pdf?index=trueIn PDF document text
    • https://4adff18d-dc39-4349-be2c-eeb12737f1cb.filesusr.com/ugd/9117e0_3063c469b2b249109c8df99e11b00e16.pdf?index=trueIn PDF document text
    • https://2cc12256-1025-444a-bacb-901a9f007bda.filesusr.com/ugd/d1fcfc_a19db5426047442ba377069c935a04a6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jidosatikim/73752277833.pdfIn PDF document text
    • https://0b7b936c-93ac-4a60-9644-6ba220b934cc.filesusr.com/ugd/b4bf80_673e7e47fb0a46679c4466b58e61006d.pdf?index=trueIn PDF document text
    • https://b7e73dfe-ad35-4791-b4f7-7500f5b7882c.filesusr.com/ugd/bc79a4_b1a4ebb01b2d4d4db25843722a1ce3b1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tuxenipup/pumek.pdfIn PDF document text
    • https://s3.amazonaws.com/fajetufekejo/daelin_hayes_injury_report.pdfIn PDF document text
    • https://b0c090b1-cb02-46d8-8a69-3fb9d82636b6.filesusr.com/ugd/4dbf3f_a5fb2960e7f74c4aae64d34a9da35da2.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/paropabaru/wojurakademalone.pdfIn PDF document text
    • https://460eb545-5389-4aa9-9e78-d1074a8bca0c.filesusr.com/ugd/21a131_693a954c423d4b79be6e49ac1d322d86.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_off0000f37d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF37D 5336 bytes
SHA-256: 9ed0a7e0602d47bab0ec1f6236521ce60f34c4823653439d334c486dba93c195
font_01_sfnt_off00010595.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10595 10308 bytes
SHA-256: bf02c66b4e1e089c60ca6ecc506fe3742c4aa8ac1c6979841775c657524ccf3c