Malicious PDF — malware analysis report

Static analysis result for SHA-256 16b720970440a0af…

MALICIOUS

PDF

84.5 KB Created: 2021-10-04 14:32:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: d469090fb7c5c2a0e91b8543a8c893ba SHA-1: 5dc7a558ef61460e227cd353a8912d83cd07acbf SHA-256: 16b720970440a0af5d1fce0eeed04d4e43fdb28b79fa9f43d9dec9b39b5fff68
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 websites hosted on compromised CMS platforms or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://crewmak.ru/uplcv?utm_term=squamous+cell+carcinoma+throat+stage+4 PDF link annotation
    • http://damosushipleasanthill.com/uploads/files/kirezerepow.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/39255145335.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/xumidana.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/75297216660.pdfIn PDF document text
    • http://jcsh.bluezp.com/ckfinder/userfiles/files/5935227932.pdfIn PDF document text
    • https://hankilfood.com/upfile/files/17928174473.pdfIn PDF document text
    • http://parmalab.it/userfiles/files/kuwexiwuwepoz.pdfIn PDF document text
    • http://beta-rc.com/upload/files/91089735718.pdfIn PDF document text
    • http://dycelife.com/userfiles/file/tubiwoselebulosuxaferase.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/50299784728.pdfIn PDF document text
    • http://zhouzhuanx.com/v15/Upload/file/202197656484937.pdfIn PDF document text
    • http://findingthegrey.com/userfiles/file/99723393270.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/wufewelevojusutebatade.pdfIn PDF document text
    • http://abyss.sk/userfiles/file/33669654984.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/50707784351.pdfIn PDF document text
    • http://joltiy.ru/uploads/files/loparogagodamukato.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6c0592035---xibojekavubinub.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/niridefekuzojetu.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16158dc9860788---tekerukuropuvegiweloda.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615288a28cc76---kepetited.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/gesebeluz.pdfIn PDF document text
    • http://zdrowejaja.com/Upload/file/35589436287.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_off0000e0e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f8f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F2 19244 bytes
SHA-256: e3412ded94b495be0804ea7ba14398150adb90cf2000b2032ed1bd6e247ee731
font_02_sfnt_off00012ad6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AD6 11076 bytes
SHA-256: e457472ea30a45eeb25cb2b06428abde94a048d4d9a1912b42f20ac21d5ba27b