Malicious PDF — malware analysis report

Static analysis result for SHA-256 838ef04564aa06bd…

MALICIOUS

PDF

87.2 KB Created: 2021-03-28 12:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7ae56a768d71f75eba1c8fd9df4e0d2c SHA-1: 7f102ddf5a27c0ad0589092353318ae889477ac0 SHA-256: 838ef04564aa06bd7af307bbd36c503b4fd959776c6c7b73e33b342a31ededdd
156 Risk Score

Malware Insights

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

The PDF file contains a significant number of external links, as indicated by the 'PDF_SEO_LINK_FARM' heuristic, pointing to suspicious domains like 'nipisod.ru' and 'zarabatyivat.ru'. The 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' heuristics confirm its malicious nature, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The document body, though heavily obfuscated, contains text related to search engine optimization, further supporting the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/strik?utm_term=what+does+warm+and+fuzzy+feeling+mean
    • http://zarabatyivat.ru/zomazaviroxi1fhqf.pdf
    • https://cdn-cms.f-static.net/uploads/4408873/normal_602e622d90e39.pdf
    • https://cdn-cms.f-static.net/uploads/4464078/normal_603f76e48b7bb.pdf
    • https://static.s123-cdn-static.com/uploads/4495244/normal_60071d5cc4620.pdf
    • https://cdn-cms.f-static.net/uploads/4404107/normal_6037c8dba8bf2.pdf
    • http://fitness1.space/alan_walker_darkside_lyrics_mp3_song_downloadndll6.pdf
    • https://static.s123-cdn-static.com/uploads/4445573/normal_5ffcb7a027304.pdf
    • https://pobanebutu.weebly.com/uploads/1/3/4/5/134592169/cda98111e1098.pdf
    • http://allwoman.site/bimekakekegavesututus6dtp.pdf
    • https://cdn-cms.f-static.net/uploads/4366400/normal_60246ea601305.pdf
    • https://static.s123-cdn-static.com/uploads/4426679/normal_5ff5902a9436f.pdf
    • https://latowinu.weebly.com/uploads/1/3/4/5/134508675/tetikos_bezorokila.pdf
    • http://shoop-ft.ru/eso_templar_pvp_healing_guideh9az9.pdf
    • http://daravto18.ru/susirarutoxavedofhvcwv.pdf
    • https://cdn-cms.f-static.net/uploads/4418391/normal_603168d343725.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://fedorahosted.org/lohit
    • https://cc4f1b1a-08c7-467e-bb5a-e3073ad8caf1.filesusr.com/ugd/ffc175_79a2d13e6bbc466ba0a11d050fc72271.pdf?index=true
    • https://s3.amazonaws.com/loranoduzuja/tewiw.pdf
    • https://436240a4-ef10-404e-ad90-c5cab949c7af.filesusr.com/ugd/3fb742_ca343fa09bc244b48615f116b29c43ba.pdf?index=true
    • https://a1b876fd-e98f-4594-996d-fc523792ae9e.filesusr.com/ugd/efcbf0_68654adc7c714273aa93b5f6cf7f717d.pdf?index=true
    • https://s3.amazonaws.com/mafavuzenoliki/hickory_dickory_dock_clock_template.pdf
    • https://e19809cf-df80-48c1-9975-8599b001ad7a.filesusr.com/ugd/062cdf_752dd29bc1a9464e855a88164fac1f6c.pdf?index=true
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001075f.bin
75aac2ba53f992cccff21a3434e402a7f29af6de3cf4cc3d2c67bdfe2041dafd
pdf-font-stream PDF embedded font (sfnt) at offset 0x1075F 5580 bytes
font_01_sfnt_off00011a54.bin
5ca81248a873e468d621ce5b346d5da705a6d65ba54743e3ba84c194e33bdce5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A54 12132 bytes
font_02_sfnt_off00014214.bin
86b02c0b6b8072a8496a27d7583aeb13732776ddd98e0cdb84032d79ce7b2246
pdf-font-stream PDF embedded font (sfnt) at offset 0x14214 2788 bytes