Malicious PDF — malware analysis report

Static analysis result for SHA-256 90201a372cd56fbb…

MALICIOUS

PDF

78.4 KB Created: 2021-09-12 18:36:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 27ddcbefec3e84abaccad3dfff20abe3 SHA-1: 099834b0eb23247278b52c4949df00646039ba46 SHA-256: 90201a372cd56fbbb33123a298d899faec1172cab625ab8c4bf020f71cea035f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The presence of external URIs and link farms on compromised CMS uploads points towards an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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=instagram+profile+anonymous+viewer PDF link annotation
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/46815732612.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/22898925089.pdfIn PDF document text
    • http://free-note.kr/files/fckeditor/file/12313428506137fb909eda1.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/74232592200.pdfIn PDF document text
    • https://blagoustroystvo24.ru/ckfinder/userfiles/files/35304198438.pdfIn PDF document text
    • https://eltechma.com/zdjecia/fck/file/filetewawubarunaxi.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/69832241000.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/zoxesapavukagopeniwune.pdfIn PDF document text
    • http://househouse.it/userfiles/files/pasoxasixejowesenixu.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/43424226991.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/4941284827.pdfIn PDF document text
    • http://bjaimama.com/data/upload/2021/09/file/202109080351532619.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/51169102878.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/55409202e7e57762029129a8d6fa67dd/razixitubet.pdfIn PDF document text
    • http://tmtechvn.com/webroot/img/files/wevijudumixud.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396bc63fa02---xeros.pdfIn PDF document text
    • http://adidravidar.com/ckfinder/userfiles/files/sagaxalobijini.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161340febc2b72---kumafonufuligevitibexa.pdfIn PDF document text
    • https://fasaac.org/temp/files/93390920482.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/13715259919.pdfIn PDF document text
    • http://everestlodgelukla.com/userfiles/file/41474554604.pdfIn PDF document text
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/8837834988.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_off0000c028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC028 22216 bytes
SHA-256: 42eaa9c9d1673294485c8283a8eda06c7e09a515f3e958c5e90c2032d00f4f7e
font_01_sfnt_off0000fa7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA7A 11020 bytes
SHA-256: 38f41e7e3e22720251b0d23e77f48f625ff5cdbe9062fce8e59c5199da35a068
font_02_sfnt_off00011427.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11427 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1