Malicious PDF — malware analysis report

Static analysis result for SHA-256 8593c3765cb3d283…

MALICIOUS

PDF

80.9 KB Created: 2021-10-08 07:21:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: de262d8654a48861146fe9ee42fd5a4e SHA-1: 45facd1683969f4c6b6273dc933d893cbbea2b12 SHA-256: 8593c3765cb3d283f99d9c0fbba153a41640c935be92b52e449ea52063ce2b9a
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF acts as a link farm, directing users to multiple websites, some of which are hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest a phishing or malware distribution scheme, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://hohsingfiber.com/ufiles/files/4911536630.pdf In PDF document text
    • https://champion-osk.pl/userfiles/file/84516987635.pdfIn PDF document text
    • http://evopizza.lt/ckfinder/userfiles/files/geratitikedefezokewotofol.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1615f92dd3b068---fisunu.pdfIn PDF document text
    • http://all-premium.com/user_file/files/sudekuzojigekasu.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/fcf05e7248e7cc5619412a1e45ace1b9/zelekonawurolilufojawakis.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/tamugeb.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/53178712993.pdfIn PDF document text
    • http://jor-agric-aqua.com/user_img/files/wujifujefekegoren.pdfIn PDF document text
    • https://keongracun.org/contents/files/soxafareku.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/44456954111.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/75751478442.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/57909269476.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/99203783376.pdfIn PDF document text
    • http://lifecontinues.ru/images/files/genazawer.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec2afa2a49---bulunesesi.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/7152853481.pdfIn PDF document text
    • http://pass38.com/images/contentimages/files/59167418400.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/32271706240.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/10510703326.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/76545944945.pdfIn PDF document text
    • http://alocainghien.com/uploads/userfiles/file/fujijukad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=detailed+lesson+plan+in+animal+production+pdfPDF link annotation
    • http://elezioni2014.gds.it/userfiles/file/42441266974.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_off0000d87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD87C 17160 bytes
SHA-256: 30ef70c1e0818a66219b0799116e5d6af6b9df71c376600db7dfc39ebae0a5e3
font_01_sfnt_off0001045d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C74 10884 bytes
SHA-256: 278dd696cd4bad7843346e9523909034be99065572abeb065c5048818afabd81