Malicious PDF — malware analysis report

Static analysis result for SHA-256 9403cdaaea928dd4…

MALICIOUS

PDF

87.1 KB Created: 2021-09-12 23:07:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 092f1c4fe50c51e90560aa9901487876 SHA-1: 79466660f09967f438a230e0a18fc64995f82042 SHA-256: 9403cdaaea928dd400fa38784fb182aaae7fab50709b4228412e32d1456227b8
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://isdoor.ru/uploads/files/64520137915.pdf In PDF document text
    • http://hz-kontejnery.cz/ckfinder/userfiles/files/18899139071.pdfIn PDF document text
    • http://vaynhe.com/upload/files/gumilulapelazixor.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/maruwowefasuwir.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/88fa17e157fdebed9209482e44c8563f/gibelagegitig.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b5ea18263---figomesud.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613937b95c6e0---rajekazo.pdfIn PDF document text
    • http://www.autoservis-hubatka.cz/admin/upload/ww/file/10225769585.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/balemolowajem.pdfIn PDF document text
    • http://dreamwith.gni.kr/ckupload/files/84769037521.pdfIn PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/74960685854.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613240536d869---linalolus.pdfIn PDF document text
    • http://ramenzoni.eu/userfiles/files/xagupuwalimobuvapaboxelo.pdfIn PDF document text
    • http://ghefootmassage.com/fckeditor_userfiles/file/bedebefujijutusopumo.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/16521679214.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4857d65ca---72244136210.pdfIn PDF document text
    • http://nenorm.com/files/files/gufatovulewalepawumujoga.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/3704907131.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=android+games+for+old+peoplePDF 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_off0000efea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEA 18236 bytes
SHA-256: 97427f4eeff7e788a433285f2adede29c21b7a46c1dc9f94040585d0a38a34fc
font_01_sfnt_off00011ef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF3 10724 bytes
SHA-256: 09eca78af78e8f307511665c7318cd92fc5b5f17d4dd60c5a3b32298db14a362
font_02_sfnt_off00013756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13756 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1