Malicious PDF — malware analysis report

Static analysis result for SHA-256 53159c8fd4cb9a47…

MALICIOUS

PDF

74.7 KB Created: 2021-04-21 12:51:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 161135b301f9124f2fcae8c7ae8da1b2 SHA-1: 588e0a172a29782cf3a4904bc521db193f8c47bd SHA-256: 53159c8fd4cb9a47cb885f7b5e1587b708d5082f7d98f1410b235d1ebeadac65
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous embedded URLs, with a specific heuristic identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. The presence of multiple external URIs, including one flagged as a link farm, suggests the primary goal is to redirect users to potentially harmful sites.

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 http://www.guninetwork.org/system/files/webform/heirri_proposals/wozat.pdf In PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/kixeje.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/geguridafaj.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/nojezajewi.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/50635107556.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/zavemazawutojene.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/96392425525.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/meratasadif.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/8474239295.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/bulurifabisiwotubavigivos.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/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=can+you+rent+an+ice+cream+machinePDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/ruwitik.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/42655509772.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/moxogugudufagelo.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.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_off0000daf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF5 4836 bytes
SHA-256: 8bf9430f825b02b6c602ae7aef88a1901a14b7cc67c84908f60bb53484341677
font_01_sfnt_off0000eb42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB42 10784 bytes
SHA-256: 38cb7622971d8cdeb1bdf5c0b7d6e72f239b09e6f877967cdfda48718d969c7f
font_02_sfnt_off00010f95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F95 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230