Malicious PDF — malware analysis report

Static analysis result for SHA-256 597458be99535404…

MALICIOUS

PDF

76.5 KB Created: 2021-05-22 02:13:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 2da85ad7379286f9bb738fadadb757d7 SHA-1: 94c3ede7e434d5b9054edfe71c2a9675196f0229 SHA-256: 597458be9953540409287260d03a8f3addf2cc89d89e7d64402d907096ccab0c
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. The ML classifier strongly flagged this PDF as malicious. The embedded URL and the heuristic firings suggest the primary goal is to redirect users to a network of websites, potentially for advertising revenue or further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • 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://nipisod.ru/strik?utm_term=dividing+whole+numbers+into+decimals+worksheet PDF link annotation
    • https://lipuxavevafip.weebly.com/uploads/1/3/1/3/131398459/1a66b5175b35b.pdfIn PDF document text
    • https://wibafodutaselo.weebly.com/uploads/1/3/1/3/131380847/4124630.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454041/normal_5fc8833edb0bf.pdfIn PDF document text
    • https://bupotovivo.weebly.com/uploads/1/3/3/9/133986694/2344895.pdfIn PDF document text
    • https://jukikekiku.weebly.com/uploads/1/3/1/4/131453151/fowozobugizola_nifefuzitudet_buxavomebopide_wirefapazofixe.pdfIn PDF document text
    • https://kopezufotixese.weebly.com/uploads/1/3/1/1/131164020/koponojogi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496816/normal_60595635b7909.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421788/normal_5ffad3a3a04e3.pdfIn PDF document text
    • https://mitumeme.weebly.com/uploads/1/3/4/8/134879381/1394847.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487906/normal_6050e8fc948cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368244/normal_601af8b328b7e.pdfIn PDF document text
    • https://pelefazefipaguj.weebly.com/uploads/1/3/4/8/134892892/sekubukozejid.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tedowafomaru/30160974636.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ada4aa0-b44c-4a96-a2fe-9d845cc83488/wenomemitolezumusosoduteb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e9a7d64-95e8-4e4b-a266-f6635bb04c5d/craftsman_miter_saw_10_inch_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf263775-43b9-436e-bfc5-98556fe0720a/adobe_acrobat_pro_2017_find_license_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24c648ba-76ff-40bd-9ce0-332970b7b827/xuvud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/19cc3ce0-6c18-4ce0-b002-5cc54bc9e485/95075502905.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4dc625ee-3676-4d37-9386-30eb8a0b454d/kopinowibewuj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b0f433f3-f2d3-47bb-abf3-ddaccca87f00/87165056009.pdfIn PDF document text
    • https://s3.amazonaws.com/rebomedug/rufivudopu.pdfIn PDF document text
    • https://s3.amazonaws.com/faxaxos/surah_abasa_urdu_translation.pdfIn PDF document text
    • https://s3.amazonaws.com/wiwuxot/boss_gt_10_manual_espaol.pdfIn PDF document text
    • https://s3.amazonaws.com/xujitezu/94113561383.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/623d2edf-16db-4241-9170-f8132cec0fe3/spanish_to_english_translation_exercises_with_answers.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_off0000ed43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED43 5708 bytes
SHA-256: 1236bee875f677cbc4e6b60a75237137a49a51491b15bd339cf9534ba4b0258b
font_01_sfnt_off00010099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10099 10484 bytes
SHA-256: 4dde756934ef62cc413caba0fd9f9b5fda884a9f863c42d75b9786c9c17bacb1