Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f81222f8413e83…

MALICIOUS

PDF

84.6 KB Created: 2021-05-20 06:01:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 253ccf190bc377e2811bd7fd891e3be6 SHA-1: 66703635da51dbe288ba81247b5f27502d4c64fd SHA-256: 79f81222f8413e83711a7249cfbc1511a1f4e61e8b877b4d4bcfc2544e0a613f
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though partially corrupted, indicates a lure related to 'vacation days'. The presence of multiple external URIs and the ML classifier's high confidence score point towards malicious intent, likely to redirect users to phishing or malware sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zajinet.ru/strik?utm_term=tabla+de+dias+de+vacaciones+por+a%25C3%25B1o+ley+federal+del+trabajo PDF link annotation
    • https://sedozexejelem.weebly.com/uploads/1/3/1/8/131871533/buleji_toxifix_xowagenonunen_lemufenumit.pdfIn PDF document text
    • https://lobududovidaxu.weebly.com/uploads/1/3/3/9/133997350/delorozufumu.pdfIn PDF document text
    • https://nivojekegup.weebly.com/uploads/1/3/5/3/135322075/9211244.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417648/normal_604b39222f03d.pdfIn PDF document text
    • https://vafadujujuzigub.weebly.com/uploads/1/3/5/3/135312713/tajusej.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372960/normal_6030603e9139b.pdfIn PDF document text
    • https://roninuvanajeg.weebly.com/uploads/1/3/1/3/131379749/1212801.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451350/normal_5fe03545b585f.pdfIn PDF document text
    • https://maxawoxemun.weebly.com/uploads/1/3/4/6/134615094/3b7420.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473971/normal_5fcfb33aa61d9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408595/normal_5ff5fe9c15682.pdfIn PDF document text
    • https://ferowadamo.weebly.com/uploads/1/3/4/5/134593689/pavebepesoxile-tutuwa-pomemupetosa-sunuzezazoz.pdfIn PDF document text
    • https://gomimujetaveve.weebly.com/uploads/1/3/1/4/131406784/niwokavi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463552/normal_602e63e366623.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414487/normal_603f2be0df7ff.pdfIn PDF document text
    • https://gopabaxofusa.weebly.com/uploads/1/3/5/3/135300850/satadojikus_fenuvidumozode_gowax.pdfIn PDF document text
    • https://magalezofutik.weebly.com/uploads/1/3/4/5/134599277/6101753.pdfIn PDF document text
    • https://ratipixudaxixix.weebly.com/uploads/1/3/4/4/134472160/b6e95c60e2fc5d0.pdfIn PDF document text
    • https://nulodikoz.weebly.com/uploads/1/3/2/7/132740439/2887026.pdfIn PDF document text
    • https://gizutiki.weebly.com/uploads/1/3/4/4/134478998/bowaweno.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tuxenipup/four_freedoms_speech_date.pdfIn PDF document text
    • https://s3.amazonaws.com/vigevot/bricklaying_and_plastering_tools.pdfIn PDF document text
    • https://s3.amazonaws.com/sojaxub/rejavejiranubumibuj.pdfIn PDF document text
    • https://s3.amazonaws.com/sefabe/16579531411.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fa78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA78 5688 bytes
SHA-256: 12b429f4a51b16ad88449c9396d587a55ce6a0e8cb04d738239e568aa4256d83
font_01_sfnt_off00010da7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA7 3280 bytes
SHA-256: 11d437a995ef6afe698ed61d1afdc21aba79e441571af780763bfde63eab34fe
font_02_sfnt_off00011ab0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB0 12048 bytes
SHA-256: eb470934d11423c72f57bea995589de0f7658b25e535cffd73f8f09b9c1e25c1