Malicious PDF — malware analysis report

Static analysis result for SHA-256 bdea8ed0b36a8113…

MALICIOUS

PDF

74.6 KB Created: 2021-06-09 04:20:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 12693e83df1f3fd54c03c6812ecaa438 SHA-1: cfb01779cfed6eb27405c7c76a389162411c5579 SHA-256: bdea8ed0b36a81137ceb6cac4a3566e6337742258f09924a2e868b51a84b4f0e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classification and ClamAV, flagging it as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous external links, many hosted on disposable domains. The primary URL, 'https://ketchas.ru/pbw?utm_term=vocabulary+workshop+level+b+unit+10+answers', suggests a lure related to educational content, likely a phishing attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • 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
  • 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://ketchas.ru/pbw?utm_term=vocabulary+workshop+level+b+unit+10+answers
    • https://static.s123-cdn-static-d.com/uploads/4401714/normal_60b64c56c8856.pdf
    • https://cdn-cms.f-static.net/uploads/4457839/normal_6026f5fe3a365.pdf
    • https://bewarovawizijus.weebly.com/uploads/1/3/4/4/134454629/9110300.pdf
    • https://lepepapiminokuj.weebly.com/uploads/1/3/4/4/134493398/7298603.pdf
    • https://pixijitawe.weebly.com/uploads/1/3/4/5/134593468/julevilupebiziz.pdf
    • https://static.s123-cdn-static.com/uploads/4392237/normal_5ff9ed24d72a2.pdf
    • https://vubupegizisave.weebly.com/uploads/1/3/5/3/135315261/8207341.pdf
    • https://xixipafo.weebly.com/uploads/1/3/4/7/134745113/vezal-porububotafi.pdf
    • https://fawurefo.weebly.com/uploads/1/3/4/4/134441885/4e6ae3c8123.pdf
    • https://nitevugumosu.weebly.com/uploads/1/3/4/5/134526644/namasorikase-vuvusodexa-dodalusalida-joxilositiw.pdf
    • https://nowabarabowuxo.weebly.com/uploads/1/3/4/3/134319250/3df10d963b1e61.pdf
    • https://cdn-cms.f-static.net/uploads/4410703/normal_60484cbe80047.pdf
    • https://cdn-cms.f-static.net/uploads/4420604/normal_6018eaada79f3.pdf
    • https://static.s123-cdn-static.com/uploads/4425224/normal_5fe06f3d1341b.pdf
    • https://nepufetok.weebly.com/uploads/1/3/1/4/131438640/2617243.pdf
    • https://static.s123-cdn-static.com/uploads/4487918/normal_600030b85be1c.pdf
    • https://wudivaju.weebly.com/uploads/1/3/4/7/134762352/6bf1e1e3.pdf
    • https://cdn-cms.f-static.net/uploads/4369655/normal_6039d8ea17e77.pdf
    • https://jozevupipe.weebly.com/uploads/1/3/5/3/135346753/2672879.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/efcf2bd1-8afc-4bf9-bba3-7938d1008672/64338338756.pdf
    • https://uploads.strikinglycdn.com/files/4c16033e-0d57-4782-9442-38a6c0c7cc07/what_should_hcg_levels_be_at_5_weeks_4_days.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4c9.bin
443ddd1aff2c5f5a2c45cc0dbd69da82a8794771f87d381e28aa05b3464ee09e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C9 5640 bytes
font_01_sfnt_off0000e80c.bin
9f8eff03390f4acaaf00b60f121afe18ba4c2e5c518c4e7eced54e2ce79afe4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE80C 2096 bytes
font_02_sfnt_off0000f1a4.bin
5a0fbbcc2866735e6d72bae6d9eef38874c975e6e32124b7c39b4e628df0d1e4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A4 10224 bytes
font_03_sfnt_off00011454.bin
1648accd5638f26481c437d0e436fdfb03edab78dab75f4e73239278c8cddc19
pdf-font-stream PDF embedded font (sfnt) at offset 0x11454 1736 bytes