Malicious PDF — malware analysis report

Static analysis result for SHA-256 25aafd016a3a676b…

MALICIOUS

PDF

97.0 KB Created: 2021-09-17 19:26:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 386ab5a1f4b06f790b335dfdb29f723b SHA-1: 845d3767c3a08263570508d49607520efdfdbc0a SHA-256: 25aafd016a3a676b2d945261fd8fa7295e09d6356f4cf91a606342c466a7fd8e
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised websites or are structured as link farms with UTM parameters, suggesting an attempt to lure users to malicious sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://pixomot.ru/uplcv?utm_term=he+man+comics+pdf PDF link annotation
    • https://12shio1.com/contents/files/99901294927.pdfIn PDF document text
    • https://bibliotheque.ville.deux-montagnes.qc.ca/ckfinder/userfiles/files/gokibonokoxewi.pdfIn PDF document text
    • http://gtlfuelmarine.com/userfiles/file/24142768772.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/79932577677.pdfIn PDF document text
    • http://yas-center.ru/userfiles/file/fodolodujunekomafuwajef.pdfIn PDF document text
    • http://pinedafoundation.org/imageuploads/file/59993527132.pdfIn PDF document text
    • http://archissimo.eu/userfiles/files/73144847661.pdfIn PDF document text
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/vabufulomurisivepa.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/nudaral.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/poritaloregaze.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/46199740891.pdfIn PDF document text
    • http://bestbuyfromindia.com/userfiles/file/nerelozewoxilufokopotopat.pdfIn PDF document text
    • http://art-ball.net/files/file/29484412137.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161449160f3b09---99557136650.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/siwekubidobono.pdfIn PDF document text
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/15870440200.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142628b5d708---58284214160.pdfIn PDF document text
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/42939717075.pdfIn PDF document text
    • http://vidiniaibreketai.lt/userfiles/file/56813686471.pdfIn PDF document text
    • http://hejia-ele.net/upload/zesukonagelanupam.pdfIn PDF document text
    • http://valsadindustries.com/userfiles/file/boxipabuxow.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/3plq8i3qtj7m95kmvfkmsihk36/30290577287.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/5ea53855d1c0e9907fc00c0dd79ebd17/50382495905.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_off00011546.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11546 18892 bytes
SHA-256: ecb6d7522a53f38aaee97fb3f37617ef0f45343fa16bd93e84c1390e8a2045ba
font_01_sfnt_off000146a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015ebe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15EBE 10528 bytes
SHA-256: 50916a670ded3e16fde6ac275ca512f928f9427f021d4dbfc5d4c65519f87c68