Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4e26fa65aad03ce…

MALICIOUS

PDF

81.0 KB Created: 2021-09-08 20:59:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 532e2bde6c40acb3bf60ad42e9bff4f7 SHA-1: aa7726f2ea9c4daaccf0e3939ddb1599e7cc3fee SHA-256: b4e26fa65aad03ce3a5624e736ad40778bca92ede995f059f43e90a281a06e4e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to numerous external URLs, many hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The embedded URLs and the nature of the heuristics strongly suggest the PDF is intended to redirect users to malicious sites, likely as part of a spearphishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • 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.
  • 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://synerhu.ru/uplcv?utm_term=instrumentation+technician+interview+questions+and+answers+pdf PDF link annotation
    • https://rt-totaalafbouw.nl/userfiles/file/ketubo.pdfIn PDF document text
    • https://snowcat.pl/admin/ckfinder/userfiles/files/86408715957.pdfIn PDF document text
    • http://canyonmeadows.org/userimages/44473280471.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/39896529296.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/4555125601.pdfIn PDF document text
    • https://zaragozadenoche.es/upload/files/fofax.pdfIn PDF document text
    • http://konikanarrowfab.com/ckfinder/userfiles/files/musaxexa.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/dariletemupunugowalu.pdfIn PDF document text
    • http://www.gleason.com.au/application/third_party/ckfinder/userfiles/files/7590693908.pdfIn PDF document text
    • https://horacebatten.com/ckfinder/userfiles/files/29171733823.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/46651206048.pdfIn PDF document text
    • http://intertexmedical.com/userfiles/files/3133361771.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16132331be97bd---kuxutajizejevixiret.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/jh4b5424dmf2rdoao3rm2gorvf/melijizi.pdfIn PDF document text
    • https://ladangmimpi.com/contents/files/gavuwuwabitazajijawiso.pdfIn PDF document text
    • https://spotiverify.com/ci/userfiles/files/12266170593.pdfIn PDF document text
    • http://explosivedevices.ru/media/file/xolimugisinasufesepofib.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132944e6ed3a---namaxufitoxutevigeva.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/xijid.pdfIn PDF document text
    • http://designbyjoseph.com/uploads/File/10445828922.pdfIn PDF document text
    • https://cape-electronics.com/media/file/nozivekaw.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/93272132170.pdfIn PDF document text
    • https://vico-immobilien.com/ckfinder/userfiles/files/31466002452.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_off0000d72b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD72B 17452 bytes
SHA-256: 050c00e9bd338f4f118dad18ca168ea5706e9d79273c724ba5666fd3f0a3ff4f
font_01_sfnt_off00010441.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10441 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C58 11188 bytes
SHA-256: 394216fe1f4d5d6697dbd91b268d7f6ca5462667858eb8fb724ca95c5ae5cf0d