Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5fca85185673688…

MALICIOUS

PDF

73.8 KB Created: 2021-05-28 10:20:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 79acfe243a7340ba148d996bd5635879 SHA-1: dc6d398442003f07210eec6c3faf5936ba17c6a4 SHA-256: b5fca85185673688ad83878d906079040fcdd1a766a17600fda065a5ee716ace
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://golowaki.ru/strik?utm_term=comparing+bacteria+and+viruses+worksheet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4462344/normal_6024f6b540b63.pdfIn PDF document text
    • https://fewabobur.weebly.com/uploads/1/3/4/7/134713859/pedavijuxurewixa.pdfIn PDF document text
    • https://lirurarupo.weebly.com/uploads/1/3/4/7/134770738/kazusenewunox.pdfIn PDF document text
    • https://warororob.weebly.com/uploads/1/3/5/3/135314520/ruzavunaz.pdfIn PDF document text
    • https://weziriditovi.weebly.com/uploads/1/3/4/1/134108838/kifipa_kikijobut_ritenutukeba.pdfIn PDF document text
    • https://linepofikoleku.weebly.com/uploads/1/3/4/4/134492010/zatuj_gobekum.pdfIn PDF document text
    • https://vufevilasok.weebly.com/uploads/1/3/4/3/134314299/gakafovika.pdfIn PDF document text
    • https://fizinizaboz.weebly.com/uploads/1/3/5/3/135304720/wadawimeral-niwida-wolepiwugode.pdfIn PDF document text
    • https://jasenumuruj.weebly.com/uploads/1/3/5/3/135309327/1508360.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448735/normal_5fe38d9eb0e48.pdfIn PDF document text
    • https://mixifotosipepe.weebly.com/uploads/1/3/4/8/134875306/xadiwu.pdfIn PDF document text
    • https://gapelovonexi.weebly.com/uploads/1/3/4/3/134385778/kizewiviwuvu_bemati_modedezoveboto.pdfIn PDF document text
    • https://magojumenuta.weebly.com/uploads/1/3/4/3/134361537/3717720.pdfIn PDF document text
    • https://fepamevar.weebly.com/uploads/1/3/7/5/137509884/4340380.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415326/normal_5fefeee0282bb.pdfIn PDF document text
    • https://nuzikufu.weebly.com/uploads/1/3/4/7/134766145/fiwibo_fepukaxeko_sepogivepavej.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/342d7107-1d70-4711-9c2f-48aa67ca78f3/bodyweight_exercise_circuit_fat_loss.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/40bcac66-2bc2-4b87-856f-eba980aa91f4/what_oil_to_use_in_remington_electric_chainsaw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d32d26cf-5eef-456f-9ae9-deab459813db/84910250402.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0398544-41a0-4c0c-acac-024b2aaf12f2/safety_moment_examples_construction.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ac748d1d-c917-43f2-a315-55cbc781ca01/banal.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_off0000e476.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE476 5716 bytes
SHA-256: 21d6f1a0b44a47ed5f3167a9608cf5df4938ed5002d818f45bdf52cdf14df74c
font_01_sfnt_off0000f7c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7C2 9928 bytes
SHA-256: e799f51830721e252750034ba7ec9cfb9c430e19c68a0df1e8b34e68eb192088