Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83390817e5049e1…

MALICIOUS

PDF

67.7 KB Created: 2021-09-28 10:11:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0d0ab71785405b20dbe0a1dbd6cfcee6 SHA-1: 272cfa501e0d72372d4b0b8093423d2dfab28bc7 SHA-256: b83390817e5049e164916d0d5b93f22cec07b468b4c7225a0165a5cc7d5535af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting it's used to distribute further malicious content. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware delivery campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b802285983---megavo.pdf In PDF document text
    • https://temahr.hr/files/16341702082.pdfIn PDF document text
    • https://spvi.cn/filespath/files/20210923115346.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613dcc4d69e56---zagalesiw.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/rezilatunelidob.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613942801cfa4---xukomizonixupefopomovumel.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/86212549738.pdfIn PDF document text
    • http://vhz.cz/user-files/zatedimegi.pdfIn PDF document text
    • http://twapp.freshkon.com/upload/files/1616606543.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/69738516574.pdfIn PDF document text
    • http://cn-polylysine.com/d/files/wamokevoterirufalenaxuvim.pdfIn PDF document text
    • http://otohyundaidanang.com/uploads/image/files/xobetaxusikejojipoz.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372ca3de155---texefozix.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/nikazekid.pdfIn PDF document text
    • http://szcftz.com/upload/2428042947.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/xupuw.pdfIn PDF document text
    • http://jar-ted.pl/file/25689316084.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/xojolodozaw.pdfIn PDF document text
    • http://noxsun.com/jingkelun/userfiles/files/20210910221347.pdfIn PDF document text
    • http://dainindo.com/Uploads/userfiles/files/1195417125.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16151437b2a073---jazexunujefutum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=android+pay+paypalPDF 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_off0000acba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c4cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4CC 15252 bytes
SHA-256: 930cd30c9640b3a046be8c82bee332c26f924935792a7d36ab1040037c4113f4
font_02_sfnt_off0000eb5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5E 10084 bytes
SHA-256: 9ffcb6cc5bbd14f89f390fb31dfbe1f37d90f8621758cd0b6562bbb7aa648b11