Malicious PDF — malware analysis report

Static analysis result for SHA-256 f33c9b7e5b43491d…

MALICIOUS

PDF

77.9 KB Created: 2021-03-26 14:56:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 66a643c74321c053751e2220b84110ed SHA-1: 0d71d44c09972d2b66bf52eee9ecb7b0217b5185 SHA-256: f33c9b7e5b43491de100953057d14cc8b6329adbdc5131f5560bf5110d442708
186 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, and it contains a significant number of external links, indicating a link farm or phishing attempt. The presence of multiple external URIs and the 'PDF_SEO_LINK_FARM' heuristic strongly suggest the document's purpose is to redirect users to potentially harmful sites. No scripts were extracted, but the overall structure points to a malicious document designed for initial access via phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://druttle.ru/award?keyword=days+of+the+week+flashcards+pdf PDF link annotation
    • https://cdn.sqhk.co/likunubiba/ihhgHLe/44147349053.pdfIn PDF document text
    • https://cdn.sqhk.co/filomada/mYhaUgg/73115638151.pdfIn PDF document text
    • https://cdn.sqhk.co/wuzufoxo/hjiibTi/fosuvofekexexa.pdfIn PDF document text
    • http://cabinetshub.xyz/javebikamuxasusoruwh6qoe.pdfIn PDF document text
    • https://cdn.sqhk.co/sebutarukaw/Hheejgq/pikolo.pdfIn PDF document text
    • http://allostar.buzz/kabebifaluxidycpi.pdfIn PDF document text
    • http://theporte.xyz/23000751046d7j6c.pdfIn PDF document text
    • https://cdn.sqhk.co/minederepa/T5mhbhg/mcdonald_s_nyc_menu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://34886cf3-15ed-44db-93e8-8979dc7c4cd7.filesusr.com/ugd/ea2c45_a3d1629d3b214af6ba6a2405ce763c08.pdf?index=trueIn PDF document text
    • https://7be8961d-effb-4c78-a255-78c3c9f0be09.filesusr.com/ugd/3dd68e_f6e992e2a17d4091aabfb90b49cb6c2b.pdf?index=trueIn PDF document text
    • https://9b704b87-3668-414c-a24e-b30400fe0e33.filesusr.com/ugd/51c472_ec009f6b31c142689807344d93af13c4.pdf?index=trueIn PDF document text
    • https://6b5d12f1-3bbc-48af-9ddb-5430d2fe15e7.filesusr.com/ugd/3bf302_9d6ea915af6f43689c37732a915ca541.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/timituvupame/67167477197.pdfIn PDF document text
    • https://s3.amazonaws.com/tutapaxi/notary_affidavit_format_for_address_proof.pdfIn PDF document text
    • https://237a2310-9536-43ad-add1-fe73b840a51a.filesusr.com/ugd/8b319d_7c333fbaaf0049e280a960322f6ce121.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/neviwove/48921417470.pdfIn PDF document text
    • https://73f4d879-981c-49fe-abc7-520f36a14a84.filesusr.com/ugd/b77b08_a8f3d5e4a60c47078ef56c0f96a6063b.pdf?index=trueIn PDF document text
    • https://728bf1be-24e3-4891-ba98-fedceca1a503.filesusr.com/ugd/3268c8_b3baba4f91854a06a3e982da58b20e1c.pdf?index=trueIn PDF document text
    • https://10bc5e17-7652-4c7e-9b43-999b3eb3b021.filesusr.com/ugd/5edc69_00c39da391d542dab5e47ca3c06f86c4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bezegoluzose/92521372791.pdfIn PDF document text
    • https://cd70d4e5-4a1a-4071-96d1-f2415ea5ece1.filesusr.com/ugd/7f46b5_3bf72c3388404ea59e85df5e66a745bc.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bubodeliza/74396957019.pdfIn PDF document text
    • https://7fe6b731-3703-45da-bcbe-faf39b4d3392.filesusr.com/ugd/880a7e_3532d19ab7ad479ea69a28c194c964e7.pdf?index=trueIn 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_off0000f322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF322 5500 bytes
SHA-256: 80cda7df48f15639424d5a408b07a0fb3fe7b256065be66d464ecfe5248f274d
font_01_sfnt_off000105f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F4 10584 bytes
SHA-256: cdba36aea2045374eda180fb33f35b32c7d2bf50a45923ef21678231ab12be8a