Malicious PDF — malware analysis report

Static analysis result for SHA-256 31418c5eb494b89c…

MALICIOUS

PDF

81.4 KB Created: 2021-04-08 02:35:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 43bb201c1b763597840ee48c84923dcd SHA-1: ecce25801625db92e781b37a11b998e6635aa255 SHA-256: 31418c5eb494b89c636b0f0f6ef587e783c935be58b2bd46d77fdd680e4ce6fa
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external URLs, with a critical heuristic flagging it as a 'PDF_SEO_LINK_FARM'. The primary purpose appears to be directing users to a large number of other PDF documents, potentially for SEO manipulation or to host malicious content, rather than delivering a direct exploit. No scripts were extracted, but the presence of many external links suggests a phishing or content distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://zajinet.ru/123?utm_term=worksheetworks.+com+scientific+notation+answers PDF link annotation
    • https://cdn.sqhk.co/vilomikov/eqhcKib/cake_decorating_classes_online_australia.pdfIn PDF document text
    • https://cdn.sqhk.co/mobovogoneja/bhjeody/91095696011.pdfIn PDF document text
    • https://cdn.sqhk.co/tagorotage/jg4genI/rezegopusixo.pdfIn PDF document text
    • https://cdn.sqhk.co/jomurozop/jaJiihc/sakatedarenum.pdfIn PDF document text
    • https://cdn.sqhk.co/zonakagud/8jhhdar/courteous_expressions_worksheets.pdfIn PDF document text
    • https://cdn.sqhk.co/jusupovexewa/ifBhbUE/57563147560.pdfIn PDF document text
    • https://cdn.sqhk.co/xiselaza/XmhjfSV/xiwazadojedixipategab.pdfIn PDF document text
    • https://cdn.sqhk.co/rekubapapup/BnydSjj/communist_symbol_red_fist.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://99f4a897-b223-4833-863a-50ad465ba5d5.filesusr.com/ugd/8e2371_afa94b9f2c294e3ea2724bcd7f6db043.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/bde6facc-e858-4133-8380-db1b7ee82b3a/15335595078.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ffa70b3d-8104-42a8-8376-298ea9b41669/tejege.pdfIn PDF document text
    • http://vamivesuger.epizy.com/ovarian_cancer_signs_and_symptoms.pdfIn PDF document text
    • http://fopivezefam.rf.gd/human_body_systems_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8741b14a-29ee-4969-aaa3-141d1e39e63f/is_interval_training_good_for_weight_loss.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/626ca436-c57f-4c38-84b4-5f6f43ff5c5c/witekozafag.pdfIn PDF document text
    • https://ba10d46a-d7c1-43af-8542-f1a50f31aa8a.filesusr.com/ugd/4dded2_a1553fd5217d48deb99885ce1d0f39b4.pdf?index=trueIn PDF document text
    • https://68a74d12-89ac-4a94-b826-09ad332a30bf.filesusr.com/ugd/1a0392_6002d777ccc6413bbe7572f9b4b790d5.pdf?index=trueIn PDF document text
    • https://da18e6a8-d720-42de-a88c-3f13daad7efb.filesusr.com/ugd/08fe48_5b310cf7869748ddbba76fb28f67b151.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5fcc6f32-b760-4b7f-83cb-27dafaadc8e8/chatal_band_dj_song_mp3_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f651b089-4b4e-43e8-8bea-f44cbef45e6d/ragamagek.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/646864d7-f3e8-46a8-9323-25902d8ed09b/75963088476.pdfIn PDF document text
    • http://fisubilir.epizy.com/tofewapufasedopaxofifijel.pdfIn PDF document text
    • https://b20aee1f-b1b7-4e4e-be5e-d884e4ece670.filesusr.com/ugd/10e3af_f9ee338f2a5f402a96af1033f0c37123.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f672.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF672 5080 bytes
SHA-256: 86c13e6014b83f976609220bc47c8113a0b26a7f0479812e009ec0733bbc8813
font_01_sfnt_off000107ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AE 9936 bytes
SHA-256: a7d4026bffd50e2c980fd88435f8460cf49323e155a5a69ca7223bd66a5c5631
font_02_sfnt_off000129bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129BF 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361

Open this report in the interactive analyzer, or submit your own file for analysis.