Malicious PDF — malware analysis report

Static analysis result for SHA-256 dda8db49627b0dc0…

MALICIOUS

PDF

67.8 KB Created: 2021-04-25 21:17:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: b07699d68d2c846a0a4a01bc9a3fd17b SHA-1: 1fb70290261e52586931b85e47f13149c1c400d0 SHA-256: dda8db49627b0dc0d1ec552669b14140d48f6fb704a9f296b078f94ed7bdb7ca
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics identified it as a link farm with numerous external URIs, suggesting it's designed to redirect users to potentially harmful sites. Although the document body is heavily corrupted, the presence of embedded URLs and the link farm heuristic point towards a phishing or malware distribution attempt, likely initiated via spearphishing.

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.enwidth.com/sites/default/files/webform/resumes/ziwisotug.pdf In PDF document text
    • https://aboss.by/sites/default/files/webform/32639212941.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/kutovaduro.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zajufofagobixipisuna.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/lipedoketuparukol.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/bogobovimefegaf.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/20598750849.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/juremetepatofuf.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/38780162719.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/71260674720.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/zMnd8XtcwSM/uplcv?utm_term=wildgame+innovations+sd+card+reader+for+iphone+reviewsPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/zotatati.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/50075528518.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bejugejotofetuxiw.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zixulupuritijidegebi.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/40347257249.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_off0000c9ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9BA 5732 bytes
SHA-256: 0ae902af53c1bb0d6cd3d825bba55625c751f0f964522d8a79a99a188ff5962c
font_01_sfnt_off0000dd36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD36 10732 bytes
SHA-256: 1c3c18012905d98e8a903ad42f95e2350ffcd129e2178b6ae8c60cf73b47c1fa