Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf75ec2902bdb56c…

MALICIOUS

PDF

85.1 KB Created: 2021-09-09 11:01:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4098a663fa8e1c97484bc591b74d9157 SHA-1: 26ba7323838cd0444d169ebd166fcc4d308f2a18 SHA-256: cf75ec2902bdb56ce39f651838bf8b2ec00557f2124b514a87bb4ca1eae574d3
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with several URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The presence of numerous external links, some with UTM parameters, suggests an attempt to redirect users to malicious sites for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://www.specemc.ru/upload/files/12925504305.pdf In PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/63803636142.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/puzadex.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/nexekus.pdfIn PDF document text
    • http://imhang.com/fckeditor/userfiles/image/sobomomirarega.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16132612c7fc65---makizibumuz.pdfIn PDF document text
    • http://www.dilipprabhavalkar.com/images/file/dofegebufibibefuzetitot.pdfIn PDF document text
    • http://kkslavicin.cz/sites/default/files/file/faniluzumutor.pdfIn PDF document text
    • http://psn-monolit.ru/img_file/files/golakadasorepejaniva.pdfIn PDF document text
    • http://rideco.hu/upload/file/timetof.pdfIn PDF document text
    • http://turinimoti.com/assets/userfiles/file/21391988639.pdfIn PDF document text
    • http://eikenhorstgroep.nl/userfiles/file/tilubedi.pdfIn PDF document text
    • http://seoulgreeter.com/userData/board/file/31547156623.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/26cad1578fb5702cf15e7121a17edc79/54249823649.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/9661228462.pdfIn PDF document text
    • http://stsaischoolamritsar.com/slbdavbatala/userfiles/file/86886215823.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/0c4c66566c75b3c659060e7a50492585/81339375318.pdfIn PDF document text
    • http://favourtec.com/attachment/file/78925702745.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/visazokirizupubalebamax.pdfIn PDF document text
    • https://basisangka.com/contents/files/fagoge.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16135f1c0ce766---buvubokiwibolates.pdfIn PDF document text
    • https://triangle-electronics.com/assets/userfiles/file/150274285.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/35407595719.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+use+skyview+app+on+androidPDF 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_off0000e6f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF03 18076 bytes
SHA-256: e28f349f2232695deee364419f3f7b08811aa3b9fe513ee7b5ac11d1d9230d59
font_02_sfnt_off00012d48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D48 10788 bytes
SHA-256: 2a27b2f8d3c354a85652664cddeed0fcbbccfa09e7cd22fe70460e50c451126c