Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d9153bf937d0312…

MALICIOUS

PDF

70.7 KB Created: 2021-04-19 08:37:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: c04c126862e8ec2a1a6014c623a72cce SHA-1: f3c22fa4068dba91af09309fd4d58b26f927006d SHA-256: 6d9153bf937d0312e5d3a591a0e2d55647e6959b540d900641d3a5e27af70f2f
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous external URIs, some pointing to potentially disposable hosting, suggests a link farm or phishing lure. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards it being used to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/padubomi.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/84972388600.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/lolavojirubopikumu.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/73261430544.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/zoxajetuvu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+do+living+organisms+depend+on+each+otherPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/53252105934.pdfIn PDF document text
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/33404153997.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c94a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC94A 5388 bytes
SHA-256: c028df79347ef9db2eb3b12099b4209971e9177adb03632edb3ca4a1eca5454a
font_01_sfnt_off0000db82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB82 10616 bytes
SHA-256: d77019bbd75eac874bf24a120073d3513d6daef5b94f3258d6e80f5700f60c08
font_02_sfnt_off0000ff9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9B 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333