Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4497fb0815bfb87…

MALICIOUS

PDF

80.8 KB Created: 2021-06-09 19:06:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0cd8f03bff79cb984374ce5549dacb98 SHA-1: 170e3ea7125774bf778258b94cb2e3322e8e83e5 SHA-256: c4497fb0815bfb8733f894c94eecb28b34fd591e280409927669540cb28a4e08
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. The document contains a mass of external links, many of which are hosted on disposable domains, suggesting a link farm or SEO spam operation. One of the embedded URLs, 'https://leonvi.ru/123?utm_term=invitation+letter+for+business+meeting+template', is likely part of this malicious infrastructure, aiming to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://leonvi.ru/123?utm_term=invitation+letter+for+business+meeting+template PDF link annotation
    • https://depopuxa.weebly.com/uploads/1/3/4/8/134893869/bapewegexenakufopo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369190/normal_605f3e2f3ce41.pdfIn PDF document text
    • https://dexugagemer.weebly.com/uploads/1/3/4/7/134715037/5205363.pdfIn PDF document text
    • https://gugebizibepowe.weebly.com/uploads/1/3/4/3/134364706/459aa4bacc9.pdfIn PDF document text
    • https://wigopezejab.weebly.com/uploads/1/3/7/4/137499336/lefumupa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404488/normal_605d313139549.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500669/normal_6051fa89b9158.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459916/normal_604289a9c89ea.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://uploads.strikinglycdn.com/files/b2b1c4e0-a8fb-4902-9319-d90d74a1ef17/zizupalenadivu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32f0beec-0ed8-46c6-8f61-bf3c64d5dd40/zojuwudufixupemupimug.pdfIn PDF document text
    • http://nadupodifado.pbworks.com/w/file/fetch/144448578/kejurimirakonatawowimax.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8e2247a-e027-4bd0-b371-2be5ab12a706/51357836075.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ba8219d2-2f3e-44dc-b612-86e2bf68820d/mujet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/65acaed0-f8f9-4b2a-a6d7-e999822169a8/jenkins_.net_core_unit_test.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1abfd4e2-01a9-4a67-afa6-5cf267313eac/67784992292.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4b345684-3649-4cee-b8d4-91e6681380c5/peuc_unemployment_california.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f70ecad2-7739-42d8-bb27-3a8fc2f8ef35/power_wheels_dune_racer_extreme.pdfIn PDF document text
    • http://nikekuva.pbworks.com/f/fufeweseb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c5609064-af11-4c99-9eab-360f991118f0/12011228422.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aaea1054-2c6e-4d3b-bfb6-02b242485c85/nokirixevupemejepi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/539174ff-0ff8-4594-ad1e-df325c851994/simple_rose_flower_drawing_images.pdfIn PDF document text
    • http://jebodigezev.pbworks.com/w/file/fetch/144523548/xunot.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_off0000f1f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F0 5240 bytes
SHA-256: c21056162e2bbaef8ded86c7b8701a722b1345468ae569073e3d9cd3e2721c96
font_01_sfnt_off000103ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AC 10388 bytes
SHA-256: 051de5e7a0fea9dba68c4629168d5a7911afffb078744473659ee48af9ac37d1
font_02_sfnt_off0001272f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1272F 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176