Malicious PDF — malware analysis report

Static analysis result for SHA-256 9be8fa5031f0d901…

MALICIOUS

PDF

77.6 KB Created: 2021-04-21 17:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 8002354d51abb70c64740fd35b559af8 SHA-1: 792428300f9d7880f2064d207ecacdae33192470 SHA-256: 9be8fa5031f0d90199b16b3aeadbdde829724c5f0705dfb7304e55f8945a3a61
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URLs and the nature of the link farm point towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://midufefew.ru/strik?utm_term=how+to+replace+ceiling+joists PDF link annotation
    • https://cdn.sqhk.co/rozesivotix/ZhhN3Wy/powazizikifote.pdfIn PDF document text
    • https://cdn.sqhk.co/vozeseseber/hPd2RGb/vunisagevawevubitazu.pdfIn PDF document text
    • https://cdn.sqhk.co/rirakibugo/hvifhgQ/42743881043.pdfIn PDF document text
    • https://cdn.sqhk.co/xurakipigub/fFiighk/yeezy_700_analog_legit_check.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6131fb9f-3080-406c-a6ab-c4686b6a2f6f.filesusr.com/ugd/52be6f_77b27a7b2ea54d468a18272c3096828c.pdf?index=trueIn PDF document text
    • https://2ddf8be6-044d-4f30-b6fd-16c032829cd6.filesusr.com/ugd/9827ea_5a1cf16961e14419a53af1115e6b263f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3c65be1b-f0c1-4165-be52-2e505c59f527/irregular_verbs_english_grammar_exercises.pdfIn PDF document text
    • https://0816b8db-db6e-4af9-a106-1766ff0f8d73.filesusr.com/ugd/06e6c8_53d019317df34c1e9cde51dfb5560204.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5bf095ae-5dda-420b-abd9-c63bc5d3dd6b/faxonozorofuxa.pdfIn PDF document text
    • https://s3.amazonaws.com/rewepalazamiso/free_android_recovery_software_for_windows.pdfIn PDF document text
    • https://s3.amazonaws.com/mejados/asus_xonar_dgx_pci-e_5.1_audio_card.pdfIn PDF document text
    • https://2f2ab42d-e0b4-4bd3-aa50-2430da1ff5fc.filesusr.com/ugd/eaf48f_2eeb082a9a2a4ee6aaeb69379255498a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tikofaketonub/what_is_the_theme_of_fahrenheit_451_part_3.pdfIn PDF document text
    • https://75ca6b5e-a470-4e0e-8004-b00a9f1721b4.filesusr.com/ugd/1e4819_9ba8ecac2b894eec8026b59bdd5c6e3a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/49762603-d5e9-46b5-b144-ce146905ad7a/robuxuzix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c400d09-6eef-4829-a595-24b3b5d95c86/71559748543.pdfIn PDF document text
    • https://s3.amazonaws.com/mesotodimus/waec_chief_examiners_report_on_mathematics_2018.pdfIn PDF document text
    • https://d4f4546a-a836-4b3d-8651-c56b89608eca.filesusr.com/ugd/3e9e83_bfd8c0b758ec4d1d92e91f1a3b0628f6.pdf?index=trueIn PDF document text
    • https://662517ce-f374-4037-aebd-99b1dbe00103.filesusr.com/ugd/0c4177_d9a3b4141c3e45d7bb33d001ee507fd3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vanatul/takifupifinubofaniwu.pdfIn PDF document text
    • https://2dc0326d-ac60-47d8-bf46-f2dc9d334570.filesusr.com/ugd/21b4a7_872b29868f684a5e9d6f02b114e2a09d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e2ed5200-898b-4d17-b143-c918afa4cde7/wojuwirasobanonesirewog.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_off0000f251.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF251 5228 bytes
SHA-256: 1172441e5384bb10ae9be79c65629a6ec39f4a3c63f2b7a23bd2b304f1436b26
font_01_sfnt_off0001043f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043F 10636 bytes
SHA-256: ef2af88c26ba3f2142a55f91454aab07860ac17b2742489e2bdc2bf3dbfad0fb