Malicious PDF — malware analysis report

Static analysis result for SHA-256 599c24f4798f3405…

MALICIOUS

PDF

73.9 KB Created: 2021-09-02 00:12:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 61a56007581128c356ad2f82ea777bc0 SHA-1: 3ff490e586d383f1d0c620905db19ff5ed00d602 SHA-256: 599c24f4798f34055ff96338b0ee1627740957374629c857810b79c77e31fd0f
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms the nature of the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608de570586e5---sexagawaruwuvozudaxe.pdf In PDF document text
    • http://rrbrentacars.com/files/others/watewakag.pdfIn PDF document text
    • http://remont-elektro.eu/archiv/file/zojoposolatowawedebefimal.pdfIn PDF document text
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1642c0dfc---kavunefagiz.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/fesasog.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/75267783026.pdfIn PDF document text
    • https://viettincapital.vn/upload/files/lezoridojubajixisukonite.pdfIn PDF document text
    • http://www.pacautomarketing.com/file/27250861996.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/91334cb2cd9033c6d75b5d0ccd18a178/vivujuvojogubiruzanuzatof.pdfIn PDF document text
    • https://kawanmto.org/contents//files/ludujetifojebujuvopidur.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16087f986b03e7---kitexebarowevikitupogiw.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/tipenamemimizifosa.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210822051207821.pdfIn PDF document text
    • https://moscreen.in/cmsfiles/file/26757455439.pdfIn PDF document text
    • http://zhxndl.com/uploadfiles/files/jeseraf.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160c344b58c324---69842154645.pdfIn PDF document text
    • http://vitacanes.com/uploads/files/tafasajoxenuxenaxaxokuxi.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/videnuwog.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160ae1f2e58803---pimowobewu.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/jemavasavole.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/80217920524.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=single+quotes+for+instagramPDF 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_off0000bb81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d393.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD393 17936 bytes
SHA-256: 2f199ea054283af6a84e59553d940a718967dc3da61580d069d6e222e48b456a
font_02_sfnt_off000101c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C8 10876 bytes
SHA-256: 5399c13767d4a8003bce885d1289787cd640799f2d11328b451aa8f666342bca