Malicious PDF — malware analysis report

Static analysis result for SHA-256 156f80d3745d177c…

MALICIOUS

PDF

67.2 KB Created: 2021-04-09 19:36:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6e7b62f9be7ab79d3835c12046300842 SHA-1: 62647b0542345f257ebb9b026adbd4144b8512b0 SHA-256: 156f80d3745d177cadd117655a87c42584977a63a616ad35644431b6edcdc1b0
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious content. The document body, though heavily obfuscated, contains text suggesting a lure related to 'sniper assassin 5 unblocked'. The presence of numerous embedded URLs, many pointing to seemingly legitimate domains but structured as webform submissions, suggests a link farm or phishing attempt. While no scripts were explicitly extracted, the PDF structure and heuristics point towards a phishing or malware distribution vector.

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.blplegal.com/sites/default/files/webform/25596831819.pdf In PDF document text
    • https://www.dgs-interparts.be/sites/default/files/muvok.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/81826716543.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/50635107556.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/41850888982.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/42042694998.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/40307308503.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dakatiwilu.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/tojawi.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/8474239295.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/vopezupudatirarib.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/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=sniper+assassin+5+unblockedPDF link annotation
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/52983615418.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/sutuzosugogaw.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_off0000cb50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB50 5500 bytes
SHA-256: 43e0f4b0b5f73f42b0cf89c6c01c4c826958315c08b0d98b1d05f5f52332f508
font_01_sfnt_off0000de0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE0A 10100 bytes
SHA-256: cc9acfb6d2ca56e541787692f41025e94d77f70bbb7feef5c323c831cd6cf52d