Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f393ce80447df57…

MALICIOUS

PDF

74.4 KB Created: 2021-05-21 12:58:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: abc478110727c4b322fd97a423d80890 SHA-1: 858ebf5fe3883e889df12bd6237993e226df1cac SHA-256: 4f393ce80447df57c51bdb95c15fc64b454410bebc87910c14bc22f922c70dac
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with one prominent link pointing to 'xajibur.ru'. This URL is likely used to redirect users to a phishing site or to download a secondary payload. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically related to phishing. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create documents for SEO link farms, which are frequently abused for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xajibur.ru/strik?utm_term=corte+bob+corto+cabello+rizado
    • https://rezemofojo.weebly.com/uploads/1/3/5/3/135321986/vivuvuxewadexilep.pdf
    • https://bawumozuvimume.weebly.com/uploads/1/3/3/9/133997273/raberuzu.pdf
    • https://jaxanawunolat.weebly.com/uploads/1/3/0/7/130739567/ravumojofokujo_momipope.pdf
    • https://lilafigofuku.weebly.com/uploads/1/3/1/3/131398347/875c42f1d91.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/f784aa37-222d-46f2-be18-ce22fb8bafa4/kebaxuduwekegemawam.pdf
    • https://uploads.strikinglycdn.com/files/8ba309ea-bf24-49ac-87f0-26a0f6d531e6/soccer_drills_for_high_school.pdf
    • https://uploads.strikinglycdn.com/files/fc5811ae-ca18-40d6-b759-8124e1ddc322/92570839588.pdf
    • https://uploads.strikinglycdn.com/files/b50cb328-7263-4a5a-8070-dc5e1315e729/the_narrative_of_the_life_of_frederick_douglass_chapter_4_summary.pdf
    • https://s3.amazonaws.com/dadupawo/vedarefaxigijiwu.pdf
    • https://uploads.strikinglycdn.com/files/94340abc-2ad1-4cee-8819-bbedbb8ba112/rixewu.pdf
    • https://s3.amazonaws.com/futamo/82551879386.pdf
    • https://s3.amazonaws.com/nimuwet/26366860586.pdf
    • https://uploads.strikinglycdn.com/files/3bcbb0f7-36b9-49a4-b4cc-7d97771d6986/68370010435.pdf
    • https://s3.amazonaws.com/regufojalojaza/everything_she_does_is_magic_sheet_music.pdf
    • https://s3.amazonaws.com/jivuxo/41367007458.pdf
    • https://uploads.strikinglycdn.com/files/95b5ad24-2f45-4e43-a076-39586c562fff/28523623326.pdf
    • https://uploads.strikinglycdn.com/files/a813813d-0807-44e6-ab3f-122893915428/how_to_get_neon_pet_rock_in_adopt_me.pdf
    • https://s3.amazonaws.com/rowubunak/valvular_heart_disease_guidelines_2017_aha.pdf
    • https://s3.amazonaws.com/wutogugej/22958980426.pdf
    • https://uploads.strikinglycdn.com/files/4f1a5d5c-dd30-4d9a-84fd-819c3b12b13d/78690926072.pdf
    • https://s3.amazonaws.com/lomiwexuva/katekunireguw.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e59c.bin
2c01fc387fdcbd0e49c2caffd6f26302860accf9c0c41b587989d3c951820188
pdf-font-stream PDF embedded font (sfnt) at offset 0xE59C 4852 bytes
font_01_sfnt_off0000f626.bin
bcbf6a4fac80342cab9f8ff94c6a0b6a69960042e150c3008ebebde18d9cec6a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF626 11284 bytes