Malicious PDF — malware analysis report

Static analysis result for SHA-256 31bdefdb540e7ef2…

MALICIOUS

PDF

80.0 KB Created: 2021-09-08 01:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 98fe074e8d55cfddd3fb4bf648947651 SHA-1: fff43c4cc87f75bba71e697d6f2dc68594879b9e SHA-256: 31bdefdb540e7ef211f998d8237452b6fc8c1faa27d42b5408f1db24a2f5e2e0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by a ML classifier and ClamAV, indicating it's likely a phishing or malware distribution lure. The PDF contains numerous links, many pointing to compromised websites or disposable hosting, characteristic of a link farm designed to redirect users. The presence of a download button heuristic further supports a malicious workflow, though no specific script was extracted to detail the exact payload delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://globalquestconsulting.com/userfiles/files/lokolasuzepeperidezowujej.pdf In PDF document text
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/mogajuwugenigujaw.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2c7e89549---fupega.pdfIn PDF document text
    • https://sikahaiphong.com/images/news/files/luwufovan.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/daluwebutijaxokudul.pdfIn PDF document text
    • http://point-grey-1970-grads.com/clients/f/fe/fe7686cf254963525dc0bd811951f15e/File/39231732243.pdfIn PDF document text
    • http://mishelik.ru/userfiles/file/puxabefiguvepiwodekajij.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d15a54db47---xewemogudefotivutavigonog.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161066d6992fdd---89252910369.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/edd3a9de0ac7336a63845be3de717da6/71254149239.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/jemufezut.pdfIn PDF document text
    • http://bangtaisay.com/uploads/userfiles/file/513169512.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/75469296318.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/fufozawavakoj.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/4es5hopopchci6orisq868joua/mukuxikopokunuxipefawojar.pdfIn PDF document text
    • https://home-consult.lu/userfiles/files/mawavazagulegakodoramok.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210625110410_801849919.pdfIn PDF document text
    • https://rajakedua.com/contents//files/pikomexe.pdfIn PDF document text
    • http://mountcalvary76.com/clients/9/90/9062e1c9f2360b2cedac6e2854879500/File/68815250390.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/fabosekol.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088f314eb3dc---fepifegupo.pdfIn PDF document text
    • http://galsabino.it/userfiles/files/88139612187.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bf9065f3fc1a580647ef1ed6790fe41b/reroxob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=rrb+group+d+question+paper+2018+pdf+qmathsPDF link annotation
    • 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_off0000cec3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEC3 11832 bytes
SHA-256: ebb12d8df4e2dd29941a874f1cd5523e8164af216760c39ef0ddd8eaec6b28a3
font_01_sfnt_off0000ea38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA38 18540 bytes
SHA-256: f5c0fb6f04ec9f8ead5bc83c8a65169c16d971e2b5be4a36e302bbd52f09455e
font_02_sfnt_off00011a82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A82 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1