Malicious PDF — malware analysis report

Static analysis result for SHA-256 74da30d550da7bc4…

MALICIOUS

PDF

76.0 KB Created: 2021-03-21 22:15:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: a039e9237312e936353c224480d2cafc SHA-1: e006e2adf1486723fe66a8a2ea3d002397ab1fb1 SHA-256: 74da30d550da7bc4555c46cbff62d45c7a5f0f3f925c7d72d2fac13535a97444
206 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating a malformed exploit stream and a link farm. The document body is heavily obfuscated, but the presence of numerous external links, including one to `midufefew.ru`, suggests an attempt to redirect users to potentially malicious content. The PDF structure and link farm characteristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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/strik?utm_term=the+secret+life+of+walter+mitty+1947+film PDF link annotation
    • http://dibuxovowo.iblogger.org/fuzanipabigarabitegizu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414489/normal_6015aea516783.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410985/normal_6021a27d53b14.pdfIn PDF document text
    • https://cdn.sqhk.co/susononuz/hejhjf3/8116213190.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490735/normal_5fe8657a287b9.pdfIn PDF document text
    • https://cdn.sqhk.co/lasanamemego/iJcDfjh/xonesazotaxefapoxamazimuv.pdfIn PDF document text
    • http://hookup666.site/fexewekawepovu7xemt.pdfIn PDF document text
    • http://13millions.store/can_you_whitewash_stained_pine2j012.pdfIn PDF document text
    • http://legiontry.online/how_to_graph_parallel_lines5rxki.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f1fb087f-5d49-4061-aa02-230b108315d3.filesusr.com/ugd/645068_f9575ff25c1743378c57f52da745381e.pdf?index=trueIn PDF document text
    • https://8a5a474a-a671-4857-921d-d1df0ee72544.filesusr.com/ugd/523716_4656edeaa91d4defb7359b4521ae4d57.pdf?index=trueIn PDF document text
    • https://b5b764bc-4fc6-48d7-9a4b-423a4d05f225.filesusr.com/ugd/3f2390_b22c23365c0743d789e0d791b0723617.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f572c82-6739-4ff4-86f1-2c95fe867edf/ironman_2000_inversion_table_reviews.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a10c390d-1c5a-44c6-bbdf-b0cb7929661d/how_to_begin_an_article_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ac9200b2-ec6e-48a4-8e4f-4402cde95162/19199318615.pdfIn PDF document text
    • http://vudasuluwiviwaj.rf.gd/yuri_on_ice_sheet_music_flute.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fe4cdfa1-6f66-41c8-aa16-c133985b3506/players_handbook_dd.pdfIn PDF document text
    • http://piwirapofo.epizy.com/jingle_bell_rock_line_dance_step_sheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e5902dcd-d9ee-436e-abdf-1e84cb535011/segejizisojofagewiza.pdfIn PDF document text
    • http://kozifina.epizy.com/94033055417.pdfIn PDF document text
    • http://gamutazuzores.epizy.com/98165674229.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_off0000e9b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B9 5640 bytes
SHA-256: 8e2d61d8d6501276a133490ff0b57166bca45573b95f8ec0f7bff50ed778b27b
font_01_sfnt_off0000fcdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDF 11028 bytes
SHA-256: 9aecc9ba6ba6130ac2490f6d94ad0cbf99687a81e770c4c66cb0bc63e219a495