Malicious PDF — malware analysis report

Static analysis result for SHA-256 53b0034179d5c511…

MALICIOUS

PDF

80.0 KB Created: 2021-04-25 21:54:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 96d35c4524e9756b7d51522ca6ea93b1 SHA-1: addfbdab20783ab433c332221ad932a34c63f3fc SHA-256: 53b0034179d5c5116e7bc096dbcb96e124aadd67691cb17b4a40d5ee9cf232e8
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The document body, though heavily obfuscated, contains references to 'Adobe photoshop serial number location' and is generated by wkhtmltopdf, suggesting a lure for software cracks or pirated software. The numerous embedded URLs, many pointing to university or organizational sites, are likely part of a link farm designed to obscure the true malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://www.osgeurope.com/sites/osg-corporate.dev/files/webform/tafunowusovuna.pdf In PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/danodajanenalidadalibebav.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/taxevoxasubosiwugudabi.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/vobefoxejajizagosoberob.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/3242210986.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/dupoxemijuwavamuvugorudiz.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ziseriwutekezarog.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/~3/3vuEKuznOb8/uplcv?utm_term=adobe+photoshop+serial+number+locationPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/mizol.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/moxogugudufagelo.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/21250884575.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/delibenapu.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/nufimogunuzin.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/sikukuditizituxabisezopel.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB8F 5444 bytes
SHA-256: 3c933cf34e1e44ae42cfc5a7ae612b9dedf8019ff460aeb10f19884fcba6b61d
font_01_sfnt_off00010dda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DDA 10732 bytes
SHA-256: e92184e83c5aa0500ba11f5739da506ec7c7b58a5fc480ef8a3578a39010c857