Malicious PDF — malware analysis report

Static analysis result for SHA-256 b138853f6af09982…

MALICIOUS

PDF

81.6 KB Created: 2021-08-10 03:45:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: 54cac4bfcab9bb03d06172c68788f7c3 SHA-1: 46acb6e6ba3b25820840cd75337645b6eae3edc3 SHA-256: b138853f6af09982de6326dfdbcae0d0dc04b6a9b0b9c66162cc90cb903ca18e
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7638

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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
  • 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.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c05f2f3212e---26158346708.pdf In PDF document text
    • https://maturana.cl/upload/file/65374146876.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160f6fb7814e9b---54073527916.pdfIn PDF document text
    • http://mamtomchabahai.com/uploads/files/files/96321898410.pdfIn PDF document text
    • http://hzqzg.com/d/files/fozujib.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/12943513680.pdfIn PDF document text
    • http://888chji.com/userfiles/files/24539540032.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/0dcc997087dbbe6a15c3bddfccb8c67b/perisugi.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/5420917588.pdfIn PDF document text
    • http://dga.gr/ILC/img/file/ruxolitinana.pdfIn PDF document text
    • https://www.visitrwanda.com/wp-content/plugins/super-forms/uploads/php/files/1470171bcf3cecb053b7ddbad3d28cab/13224737310.pdfIn PDF document text
    • http://benrassam.com/uploads/files/luzipogesusepaxiruz.pdfIn PDF document text
    • http://2ds-creations.fr/userfiles/file/42722155277.pdfIn PDF document text
    • https://civilkontroll.hu/uploads/file/55687183100.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/xuronibeluvosazalur.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/89004215104.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/bdf503906908217a81af623cf4199699/luweda.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/kunedovidemomene.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160858279f0958---46648373477.pdfIn PDF document text
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/58e859480de8b51bd514997e44bd39b1/fejuxokovoxonigoraji.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/cfa8e54fd9c136bf92d0329bcc8a594e/vomopevomir.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/vcu6k4cb9p43abs7hbgljnc681/kinukipopijojipep.pdfIn PDF document text
    • http://aiken7050.com/clients/5/51/510ae66c864a6d23552e02d1b5190e2c/File/fumepagapakafov.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7cbe14d9ee---fipusufep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=here+comes+the+sun+piano+sheet+music+%28easy+free%29PDF link annotation
    • 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_off0000e9ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9EF 16904 bytes
SHA-256: 24649936bbf2a5cc29b329aa4c72ca0b113a9a8d67d05b7e4784d570df0914fb
font_01_sfnt_off00011636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11636 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012e4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E4D 11060 bytes
SHA-256: fe5ab6bb1d4bffa29dd7f9acdc02dbd404b09ae1e05c845616bd5fca0745b37d