Malicious PDF — malware analysis report

Static analysis result for SHA-256 77617b9da28405a7…

MALICIOUS

PDF

64.3 KB Created: 2021-04-25 23:32:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 914d4d6efafc469e467364aabe09685c SHA-1: de1054880749242bce8733ec8f79152ea83659b4 SHA-256: 77617b9da28405a7a5836db59bcc524494f02526a61aa552a8ef4bead7cb3260
124 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are hosted on seemingly legitimate domains but point to PDF files, suggesting a link farm or redirection tactic. The document body, though heavily obfuscated, contains text related to a chemistry worksheet answer key, which serves as a lure to disguise the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9819

Heuristics 4

  • 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
  • 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://www.mothercare.ro/sites/default/files/webform/resumes/tawapiseligimagawawujimo.pdf In PDF document text
    • https://www.blplegal.com/sites/default/files/webform/vogelunejubujapezidugave.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/tikat.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/zivexovoburowunaxomenip.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/31226501773.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/66271497470.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/nozixedexifanozavarojiro.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=chemistry+balancing+equations+worksheet+1+answer+keyPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/siwujomizawafoxewop.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/9071701793.pdfIn PDF document text
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/kizoromafogikigogusebef.pdfIn 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_off0000c646.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC646 5692 bytes
SHA-256: 0afc0e4a6f9fadb18ae64e06fec487ed36ed5ef1ac11189d643f0610a99f8cbc
font_01_sfnt_off0000d99b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99B 10452 bytes
SHA-256: 4e16da3dad85706d8f2210ce413b79570933b4e1cb13a2f8812373d00ab125b4