Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd183c7e017d8577…

MALICIOUS

PDF

62.6 KB Created: 2021-04-06 21:51:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 1c1fff0bbcf2637eeea7244c09dd5564 SHA-1: 7aeef911bd49fc8c6a2f2bd05e5d3cd8e3422490 SHA-256: bd183c7e017d8577f2605d63015336855d3438264a0ea1a484ea686752c1347b
126 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains. The 'ML_NYX_PDF_MALICIOUS' heuristic and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to be a lure related to 'ammonia toxicity in fish pdf', likely intended to trick users into clicking the malicious links.

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 http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/40041164747.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/58588935603.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/99368311749.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/85138354947.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/71926652616.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/25680057182.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/lewuxevibonotokezesa.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sowasipaxezok.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/90877516301.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=ammonia+toxicity+in+fish+pdfPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/ruwitik.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/98562832035.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/siwujomizawafoxewop.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/58023923203.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_off0000baca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBACA 5428 bytes
SHA-256: e000d523639f96c708c5c4f9dcc1ac72b4db0ea9ec576eb10950c1dfb4524650
font_01_sfnt_off0000cd2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD2C 9512 bytes
SHA-256: db9acaefa89953d5ec57c8df11910a3eaab84522790000f72aa0eb26f522a795