Malicious PDF — malware analysis report

Static analysis result for SHA-256 61fb1377b4737ee1…

MALICIOUS

PDF

81.0 KB Created: 2021-05-13 15:24:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: fa50ebfc0e71bd824cf7249dd46ab570 SHA-1: 43a40e335f91b589f23983ecfe449208623018a3 SHA-256: 61fb1377b4737ee1429236a95bb59ac664f2fd8186cd691662266a23ab524373
186 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a malicious SEO link farm, containing numerous external links to other PDF documents hosted on various domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for distributing further malware or engaging in phishing. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's part of a larger malicious infrastructure designed to attract traffic and potentially deliver payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://gimoguvi.ru/strik?utm_term=scientific+method+worksheet+elementary+pdf PDF link annotation
    • https://cdn.sqhk.co/begokaxawip/jQGghhe/1967_super_snake_eleanor_mustang.pdfIn PDF document text
    • http://health2health.online/74724403605i669g.pdfIn PDF document text
    • https://cdn.sqhk.co/kivipemo/gciihgY/luzelak.pdfIn PDF document text
    • https://cdn.sqhk.co/suwinodujeja/2heiii4/camila_cabello_age_15.pdfIn PDF document text
    • https://cdn.sqhk.co/mifigatira/fijje4Y/monster_truck_show_2020_jim_falls_wi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470841/normal_606aa36c40720.pdfIn PDF document text
    • https://cdn.sqhk.co/fegujajox/igvjd0B/social_media_strategy_for_nonprofits_template.pdfIn PDF document text
    • https://cdn.sqhk.co/ripalufix/2ijijZw/pamujupaxet.pdfIn PDF document text
    • https://cdn.sqhk.co/zifeduwa/ihjajXe/93589835969.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472753/normal_601972cd28887.pdfIn PDF document text
    • http://pl50off.info/12_traditions_short_formkp750.pdfIn PDF document text
    • https://cdn.sqhk.co/tuwetebep/hiaijig/note_taking_strategies_while_reading.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483089/normal_605232560bbcf.pdfIn PDF document text
    • http://smartcreditscore.info/dokojorukexevatuka4qcyv.pdfIn PDF document text
    • http://g2am2e.xyz/medialink_router_reboot1cnr0.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://f4e740b0-69d0-4d5c-a0c7-362dc6b2ad6d.filesusr.com/ugd/0356fc_bffec6a6c47d4b10b011d956cd2fd5ce.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/608da7c5-a16b-407a-ac11-5701d021ebb5/75258289721.pdfIn PDF document text
    • https://66c7139a-03c0-45fe-98d3-e817d1e01442.filesusr.com/ugd/de2db5_ac327a9900f94993abd9c96678ecffe5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/57bb8886-23dd-45e5-9796-4d4303926a94/ziletagedixetisuvad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e02164f-4fcb-4420-b39b-9f03ccb3765b/lewafixufarifeniwipoxa.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eecd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECD 5544 bytes
SHA-256: 2728197c36c51b9532c38b25ba1cf7c54233d18b34078cad483e6457ccf475a1
font_01_sfnt_off0001017f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1017F 10972 bytes
SHA-256: b469d5b8c99481a79e6bacb4318d93272daf7a32c6f991c0d37df10f36d9f7b0
font_02_sfnt_off000126f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126F5 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3