Malicious PDF — malware analysis report

Static analysis result for SHA-256 0725435d1108a5e4…

MALICIOUS

PDF

76.3 KB Created: 2021-06-09 09:58:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: cb2d15fa6faad9c145d42fae7c71fabb SHA-1: 10ee1cd8e952c7e220643b1a7702994cba50644c SHA-256: 0725435d1108a5e465e0776ff058842998be0fcb0a0a7bb8477ba4a25a12126b
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 designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent. The presence of external URIs and a link farm points towards T1566.001 (Spearphishing Attachment) as the likely initial access vector, and the potential for exploitation of PDF vulnerabilities suggests T1203 (Exploitation for Client Execution).

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://vilenefex.ru/123?utm_term=water+cycle+diagram+worksheet+4th+grade PDF link annotation
    • https://xixurisegiwawaz.weebly.com/uploads/1/3/4/0/134012782/c1259ff8c.pdfIn PDF document text
    • https://vexigijetizi.weebly.com/uploads/1/3/4/7/134771524/niremivazufu-zovasowinate-pegos.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448718/normal_6047977ed7b35.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486368/normal_6020289737f8e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385011/normal_6028fc17ef722.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478393/normal_603cff7512ca5.pdfIn PDF document text
    • https://luribexibaw.weebly.com/uploads/1/3/4/7/134750384/609d35c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478932/normal_603e6757a891f.pdfIn PDF document text
    • https://nebomigefut.weebly.com/uploads/1/3/4/3/134359696/0c8dd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471085/normal_6011380da5772.pdfIn PDF document text
    • https://fefojaza.weebly.com/uploads/1/3/4/4/134480993/fezub-nebirojujumozob-duxuz.pdfIn PDF document text
    • https://mifadumuvuvog.weebly.com/uploads/1/3/4/6/134689338/dd308f82e64598.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/79c94acd-1c55-458c-a90c-e7956a2fde40/dibepezopaju.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35e71e49-faeb-43c4-8b9b-bab6c17d14fc/17849321921.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f1acf80-defb-41fd-89a6-ff3b707f558f/gofewipajosoxedijewi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4e48ea1b-9daf-47b4-9731-e392795847be/infractor_significado_dos_nomes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f181197-3e1b-4ae2-83c4-6b2a8a0a4bc9/45735761680.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5aef4fd3-a06d-4b0b-895f-219518ffd391/girl_boss_sophia_amoruso_vk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a80129fc-0a30-4ab5-a754-ba00c240bc86/hp_smart_tank_515_price_in_kuwait.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_off0000edc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC5 5712 bytes
SHA-256: a5471857618c2c7afe0c547af2d2f5200a3c4edc4e89899a49e9bede95f6e77f
font_01_sfnt_off00010137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10137 10092 bytes
SHA-256: 2f89829b17a6626f775ad8862ffa64010cffdc8ea798635419ae75c994ffc07a