Malicious PDF — malware analysis report

Static analysis result for SHA-256 61cfe2537637db5c…

MALICIOUS

PDF

81.1 KB Created: 2021-10-08 04:12:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 021832d72a4f36307fe271f8ea3c79cd SHA-1: 80b0233fa4eb436175725f98d529322a21157c79 SHA-256: 61cfe2537637db5c17c05df1abf4cde04159bee4eaaa7f234de0ef5b0def038c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to external sites, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • 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 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://laborke.ru/uplcv?utm_term=how+to+get+whiteboard+marker+out+of+clothes PDF link annotation
    • http://myxroad.net/upload/userfiles/file///87052454987.pdfIn PDF document text
    • http://biblioteka-belzec.pl/upload/files/45275102457.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/giporamoraripejunolug.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/xegebixiwikasapezew.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/93431434132.pdfIn PDF document text
    • https://fontaine-eva.fr/userfiles/files/68292693438.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/kozatedigomigaxorem.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/36293031045.pdfIn PDF document text
    • http://hanart21.com/files/userfiles/file/jajibuwovisimixorife.pdfIn PDF document text
    • http://cafegreenwichvillage.com/uploads/files/gajinesafizasir.pdfIn PDF document text
    • https://ooobelkom.ru/ckfinder/userfiles/files/96227196507.pdfIn PDF document text
    • http://4bx.pl/public/file/nerevolezuxunodibuma.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/xejikaziverulanavofu.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/bd535f1hcic5gnpaq1r8lcjf09/tibifasipitutuzeve.pdfIn PDF document text
    • https://sibois.eu/userfiles/file/40335013088.pdfIn PDF document text
    • http://zbraneklapka.cz/ckfinder/userfiles/files/xokanasazagumulebipefaz.pdfIn PDF document text
    • http://monyetmesum.com/contents/files/22346822773.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/jakatefodelodenidofekaxo.pdfIn PDF document text
    • https://ljlconst.com/admin/images/file/78393539690.pdfIn PDF document text
    • https://czus-lukasa.sk/userfiles/file/45067190536.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/gixasu.pdfIn PDF document text
    • https://mbbs.hr/files/28624430288.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/547644136615cd28b78936.pdfIn PDF document text
    • https://aiwatopup.com/ckfinder/userfiles/files/popanabipufowusezeroxaw.pdfIn PDF document text
    • http://autovoda.ru/upload/files/tezamupugeregaxine.pdfIn PDF document text
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/pixesomovemudikupis.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD473 18124 bytes
SHA-256: d61513218aa1c90f95197bfa1e8efbdcedad7c1b61fe7b6c7eb4071e6e82d12e
font_01_sfnt_off000103a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBF 11228 bytes
SHA-256: 8f1578a8409bab0d956f773dcc4af9fc006a2e3ada31ad1bf3e0b52c199f2139