Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff6aa41d480eb2ae…

MALICIOUS

PDF

77.5 KB Created: 2021-02-10 19:35:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 97db7e6ee743e74c3c9b0bfdd5cd7814 SHA-1: eab1abf9057038b6565ce8f228a024b0f8098aa3 SHA-256: ff6aa41d480eb2aec7dfd8a59163e72cdb1c620dda772090a9aa33d0c70d5ebe
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate maliciousness. The document body, though heavily obfuscated, contains text that appears to be a lure for "activity 2.1 3 aoi logic implementation answers", directing users to external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://seumenha.ru/123?utm_term=activity+2.1+3+aoi+logic+implementation+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4416319/normal_60202f78321a5.pdfIn PDF document text
    • https://kopepadozuko.weebly.com/uploads/1/3/4/5/134505487/mupave.pdfIn PDF document text
    • https://cdn.sqhk.co/mapiwoda/wTsiiaH/ricky_carmichael_motocross_apk_free_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369516/normal_6023624b3b70a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375507/normal_60159244e0d17.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393020/normal_600ccb552b4a0.pdfIn PDF document text
    • https://vopasigujar.weebly.com/uploads/1/3/0/8/130813381/takobugoj.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373240/normal_5fde272e9d54e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454550/normal_602080101226b.pdfIn PDF document text
    • https://vufagejibuto.weebly.com/uploads/1/3/1/4/131483336/1e2c880eae997ab.pdfIn PDF document text
    • https://cdn.sqhk.co/joraxeneli/hgZlRjh/hashtag_generator_app_best.pdfIn PDF document text
    • https://goxatuzibifonev.weebly.com/uploads/1/3/0/7/130739188/nazadivitareso-ragujotukidowel.pdfIn PDF document text
    • https://xuxukogizi.weebly.com/uploads/1/3/5/3/135320654/7046978.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412774/normal_600043b89530c.pdfIn PDF document text
    • https://sazejibapox.weebly.com/uploads/1/3/4/8/134863873/nuregalixage.pdfIn PDF document text
    • https://cdn.sqhk.co/nezerozara/sXMfzij/55528696116.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416327/normal_5fd8bd44424a2.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In 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://s3.amazonaws.com/lekizopiloref/mikikix.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD761 1692 bytes
SHA-256: 8493deba7ed7f44956163bb6b82250685fe722451f641cf34a86f13fd545fa92
font_01_sfnt_off0000dfbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFBC 5664 bytes
SHA-256: d90ec707de306517e95d3fd9c374ef0bf7ace1b9ec10a3cee8c8374b00d3ac1d
font_02_sfnt_off0000f30a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF30A 10852 bytes
SHA-256: 24cf29509ba8d5c2dc20d012ed313f42607bb29e2c343d7de5e3d33a3ca290fd
font_03_sfnt_off000117f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117F8 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34