Malicious PDF — malware analysis report

Static analysis result for SHA-256 3efa0978a792cb83…

MALICIOUS

PDF

91.7 KB Created: 2021-05-31 09:01:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 6f10ea79b74a71d62474991e7522e9af SHA-1: 86a08c1c7dcfde9f23190bcdf29e9195155e4ed5 SHA-256: 3efa0978a792cb8315678bc9da7689a47f15054278df75138088cb95b1aa5ce6
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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/strik?utm_term=a+concise+introduction+to+logic+exercise+1.5+answers PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4475874/normal_5fdd89ef74d23.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4422658/normal_5ff5fd9f9684a.pdfIn PDF document text
    • https://pefoduzipim.weebly.com/uploads/1/3/4/3/134371740/203a6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387424/normal_6015fc16cccbe.pdfIn PDF document text
    • https://mokadipubozot.weebly.com/uploads/1/3/2/3/132303064/6561987.pdfIn PDF document text
    • https://fokifukamanur.weebly.com/uploads/1/3/0/8/130874497/fejer_wekufadusiwevuw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368494/normal_6030ddc001c2b.pdfIn PDF document text
    • https://meverofukibax.weebly.com/uploads/1/3/4/6/134620555/ribovi.pdfIn PDF document text
    • https://gesinanafu.weebly.com/uploads/1/3/4/4/134481382/8581293.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://uploads.strikinglycdn.com/files/36c7ff32-a077-4f82-96a8-c557abd96880/srs_tool_app_apk_download_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2369942b-2deb-4ab9-8677-541e23f7a39c/11526747652.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/20d24631-6cc6-4b09-bf48-b4a4cb5f52e9/what_is_average_weight_for_height_and_age.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0c01a929-b2df-4102-95d5-b2dd9ca79672/graco_pack_n_play_bassinet_set_up.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/73a6fc2e-b238-402e-8df6-96daf284dbdb/visomirefepeka.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98a4c194-b9e7-4256-a16e-584cc1d2f771/how_much_are_sundance_spas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04852982-5ff1-4c3d-805c-073ebb5453ae/dojemewitisafomolo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8855b9f-13b4-4ea0-b676-539a6d71782b/lofedigusogewewagiv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/acd2859d-3a0e-4e69-9868-a83138acd725/lopafigafiwiworika.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f806fa3-66f9-404c-a1e7-d94144ce7879/zomegipiz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8d96691c-8780-4a04-b766-0a279caac29b/tudedan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/afca291f-8995-46b5-b9a3-fb8b83e865d4/5215303085.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd74fc6c-6be2-4f1a-b186-ba99f6e64903/sopotafazajutabutemiraj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/baede2ac-f223-44ca-9343-90820598b376/tutajekawirirumegevifepij.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/362c4c64-7cc0-4a9f-9260-aac9c41782c4/sotutokowibonovagovoxevu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ad10535-b69f-477b-a3e9-f145675ee19b/vapawukunaje.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64af6282-183c-4826-bd03-3d3a78494c80/sopokige.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43eecddc-8f71-440b-bd82-a6ea42e0d404/how_to_see_book_thich_nhat_hanh.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F7 5344 bytes
SHA-256: ae1ae22ab4f8348803c8d6687f5bb573f3f07dfc0d803bb83e79133e2d4eae20
font_01_sfnt_off0001083d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083D 2116 bytes
SHA-256: 316f78c6e162999e43ccb83d429ef85c46045bf1ac59c77d169faf589ecd4eba
font_02_sfnt_off000111e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E7 12564 bytes
SHA-256: d978cc2b6d3ae4f028746a63a9b84d8ac50509bf413b0d6ee127e4fe27d5ac5c
font_03_sfnt_off00013ac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AC8 16076 bytes
SHA-256: f530883c3cc306000364b4084cae578ea9cd0c162069bd297b59107afb5012c9
font_04_sfnt_off00014f70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F70 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361