Malicious PDF — malware analysis report

Static analysis result for SHA-256 dec0941d628728f8…

MALICIOUS

PDF

69.5 KB Created: 2021-10-03 00:02:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 36d21babb0ad546c14f1e979ad3c1be6 SHA-1: df6339a794e7f14f49c52656c6a3baa85e201158 SHA-256: dec0941d628728f8f23eabc9c21ae1dd72ecc53120abc7ce458e07ab40df4eac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a link farm. It contains numerous URLs pointing to compromised CMS uploads and disposable domains, suggesting an intent to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://catamma.ru/uplcv?utm_term=isoclines+differential+equations PDF link annotation
    • http://konberdbio.com/upload/files/xefinusosulo.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613618581f01a---kezevukaxedabawizuviv.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/c63b72db18834733a15d88146d3d388f/rugepukaramizesarebolamum.pdfIn PDF document text
    • http://liluby.com/upload/file/ziligovalukazivarojovefep.pdfIn PDF document text
    • https://fwstc.in/userfiles/file/1742804230.pdfIn PDF document text
    • https://vrrc.heart.net.tw/ckfinder/ckfiles/files/81663271177.pdfIn PDF document text
    • https://webmenuplus.com/images/file/51608027348.pdfIn PDF document text
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/94990471940.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/tawelid.pdfIn PDF document text
    • https://houstoncoinclub.org/FCKeditor/file/40483919111.pdfIn PDF document text
    • https://stvorki.ru/files/file/32989472204.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/koxisen.pdfIn PDF document text
    • http://synhbio.com/upload/files/lajav.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/kolajojuvimevuxaletin.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/44863413820.pdfIn PDF document text
    • http://magdrywall.com/project-new/christianbook/upload_images/file/7647855979.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e5c985b66---galek.pdfIn PDF document text
    • http://nontaromclinic.com/ckfinder/userfiles/files/94888563184.pdfIn PDF document text
    • http://pinturasoltra.com/images/slider/files/55460452139.pdfIn PDF document text
    • https://foodsafebox.com/ckfinder/userfiles/files/57446707910.pdfIn PDF document text
    • https://kamarkosong.com/contents/files/64609692540.pdfIn PDF document text
    • https://enilubricant.hoakhanh.vn/uploads/image/files/78218969224.pdfIn PDF document text
    • https://www.scmsgroup.org/ckfinder/userfiles/files/duzozalinisogodis.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_off0000af2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF2A 16196 bytes
SHA-256: b15f2b957d82ee1ea8f20eb3e7c79b686d3f4f2503ab3a35658b3005db9ec482
font_01_sfnt_off0000d83b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD83B 10664 bytes
SHA-256: d0f33578e2a7684916238296e50ef158577e45c7e8e317ccf5ca94d917efa885
font_02_sfnt_off0000f094.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF094 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1