Malicious PDF — malware analysis report

Static analysis result for SHA-256 05728c7c71250b24…

MALICIOUS

PDF

98.3 KB Created: 2021-03-22 23:37:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 116aede18a17ffc480468e683b41aacc SHA-1: 1323a8dcfc5807ab9a077cb736c199e3bd468964 SHA-256: 05728c7c71250b249f684cfc1871778f265fa47c0114ffe7dd2e2c2e30773d24
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to direct users to malicious sites. The primary malicious URL identified is 'https://midufefew.ru/award?keyword=bacillus+subtilis+bacteria+pdf'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

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://midufefew.ru/award?keyword=bacillus+subtilis+bacteria+pdf PDF link annotation
    • https://mapobosani.weebly.com/uploads/1/3/4/3/134385232/4832006.pdfIn PDF document text
    • https://devanuwi.weebly.com/uploads/1/3/0/9/130969177/1194725.pdfIn PDF document text
    • https://lobobofu.weebly.com/uploads/1/3/4/6/134680821/maxamexo.pdfIn PDF document text
    • https://ledajesaler.weebly.com/uploads/1/3/4/0/134041179/2452064.pdfIn PDF document text
    • https://fodukajanewirom.weebly.com/uploads/1/3/5/3/135383911/ligifepize.pdfIn PDF document text
    • https://xojurumute.weebly.com/uploads/1/3/5/3/135328527/be55c2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4487413/normal_5ffa33dcc09e3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484997/normal_5fc9e87a64416.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://87c8fc71-818b-4167-bf0d-2ac3bc49ffd1.filesusr.com/ugd/f9d4cd_0dcdcfd0062a4902b10996f9ced6ace0.pdf?index=trueIn PDF document text
    • https://3d73ec66-e24e-4607-99a5-aa3c333c10ea.filesusr.com/ugd/a96454_b48ba1faea4a4a4b8f308260017d05a9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/829dbb86-4087-42b7-9ffe-a66cfca9fb74/is_company_of_heroes_2_free.pdfIn PDF document text
    • https://s3.amazonaws.com/kaxukok/nakunisiwigofowamoxeka.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/724ffc4f-8533-42cf-b480-58823d0564dc/watch_little_house_on_the_prairie_season_6_episode_21.pdfIn PDF document text
    • https://a40b6db0-1679-4e03-879f-ac5827b9aa7d.filesusr.com/ugd/dba42a_fa4d5a0fdd7649ca95e943491b20a38f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bokofapig/ribosome_peptide_bond_formation.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b290d5a8-775a-4229-97a2-52bd1311a1c8/kifimiwanobej.pdfIn PDF document text
    • https://s3.amazonaws.com/lopadivupudexa/22158633542.pdfIn PDF document text
    • https://6db1e9a2-4282-4636-8d41-de07325ad911.filesusr.com/ugd/d97b38_832ecfe2946e40e7816bd4db2725e252.pdf?index=trueIn PDF document text
    • https://53ebb62d-ddaf-432f-8dc3-1f4746653467.filesusr.com/ugd/bbd3cf_ac2320be91244fb8bc1d2ae370fc7a2a.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_off000141db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141DB 5336 bytes
SHA-256: 341a5c6368354a78927140e1557f1a2d71a6a7e2f4c1a900e2992458287d1559
font_01_sfnt_off00015406.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15406 12432 bytes
SHA-256: 80bf2befe45244e55d5295c6d67c6a740f4488ba093114100a80e4cf0f367f1c