Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a551f2636b0758…

MALICIOUS

PDF

69.3 KB Created: 2021-03-25 19:43:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: ee32d2b5111e26a1e5b48bc96e9d1400 SHA-1: c23768cc98078db410eeb977090b17162aea8412 SHA-256: b4a551f2636b0758ca80a7dd6f473922fe477e004c1b1a2f7d1a3f55d2413463
196 Risk Score

Malware Insights

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

The PDF document is identified as malicious by multiple heuristics and a machine learning classifier, specifically flagging it as a phishing or trojan. It contains a large number of external links, many of which appear to be part of an SEO link farm designed to redirect users to potentially harmful content. The primary lure is presented as 'Articles in english pdf exercises', but the underlying structure is a redirector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://botokaw.ru/123?utm_term=articles+in+english+pdf+exercises PDF link annotation
    • http://rixokufofaru.iblogger.org/libros_de_fisica_caida_libre.pdfIn PDF document text
    • https://dojifidixiwaji.weebly.com/uploads/1/3/4/3/134372722/labulisedegudup.pdfIn PDF document text
    • https://kubazabuz.weebly.com/uploads/1/3/4/8/134885093/417087.pdfIn PDF document text
    • http://fezanabuxa.22web.org/19933647282.pdfIn PDF document text
    • http://doresal.22web.org/bailaras_full_movie_free_hd.pdfIn PDF document text
    • https://bapajoronugenig.weebly.com/uploads/1/3/4/2/134234589/85f2f8835f.pdfIn PDF document text
    • https://dulipitigisol.weebly.com/uploads/1/3/4/7/134717891/92e95d4c.pdfIn PDF document text
    • https://senamevab.weebly.com/uploads/1/3/4/6/134689233/3971055.pdfIn PDF document text
    • https://xaperosojemi.weebly.com/uploads/1/3/0/9/130969510/wodakevin_sobijewuzab_sopax_ligek.pdfIn PDF document text
    • https://tubolapibakosi.weebly.com/uploads/1/3/4/8/134872187/ef3786c744b4d.pdfIn PDF document text
    • https://ximepovefuvaxoj.weebly.com/uploads/1/3/1/8/131856443/6724988.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/tenunud/jurufudamopubiputezovu.pdfIn PDF document text
    • https://s3.amazonaws.com/donarepemi/tijamaluzutujedojimexigen.pdfIn PDF document text
    • http://dexixikix.epizy.com/beaglebone_black_getting_started.pdfIn PDF document text
    • https://df9240ce-57b4-430e-a582-521170ca5232.filesusr.com/ugd/10b03a_55df92866460458eb0b14c62d6cfdcd9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bufexa/80025102158.pdfIn PDF document text
    • http://suzoduw.rf.gd/cute_attractive_wallpaper.pdfIn PDF document text
    • https://s3.amazonaws.com/fasudikek/82052094732.pdfIn PDF document text
    • https://s3.amazonaws.com/tanikanaw/17464998164.pdfIn PDF document text
    • https://4c8e72c6-e2e3-4108-adc6-102de481692d.filesusr.com/ugd/f4b4ca_64d35c4fbb9a4b399eaf2530a8b193c4.pdf?index=trueIn PDF document text
    • http://jubidak.epizy.com/angielski_w_tumaczeniach_gramatyka_3.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_off0000d264.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD264 5264 bytes
SHA-256: 6c5e3c1c64e5d19de4289972dfc8b1ccfcb1a4364fcbc1dedb2cbffbbd8a01ed
font_01_sfnt_off0000e454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE454 10424 bytes
SHA-256: df6a7e19f171b5207b469142d1a9f759d4d5a589d1dc4a2e4e2a7756781848b5

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