Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b3ad1abe5c5a2ad…

MALICIOUS

PDF

69.7 KB Created: 2021-09-13 22:09:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 19afc0f5c1c79068812371cf0465c562 SHA-1: b17436e48a3b25b0cfa80642c8c3bddf3c15d28a SHA-256: 1b3ad1abe5c5a2adb5495ee827317d20f3f97bd124727104605915a76e0c2977
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous external links, many pointing to potentially compromised WordPress upload directories or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated, but the presence of external URIs and link farm heuristics strongly indicates a malicious intent to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://catamma.ru/uplcv?utm_term=video+calling+on+pc+to+phone+free PDF link annotation
    • http://plncse.hu/php_data/file/zaxovo.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/17246231448.pdfIn PDF document text
    • http://cosmik-kinoteatr.ru/sadm_files/mepukumozefogaxojum.pdfIn PDF document text
    • https://aczv.fr/userfiles/file/91263911977.pdfIn PDF document text
    • http://dongduong.net/Images_upload/files/9906862260.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/26537169834.pdfIn PDF document text
    • http://cke.hk/userfiles/93658270515.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fac4c23696---wumubisodijudafexob.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/tadex.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/38ba16d63ba881151c44e550ae5008a4/68704449742.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/74587286992.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/603b785036a27a32acf5b7fd16594f18/94374097021.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/sabakakone.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/jedewisumuwuvukonogejar.pdfIn PDF document text
    • http://studiomistretta.com/userfiles/files/molap.pdfIn PDF document text
    • http://istanbulballoons.com/ckfinder/userfiles/files/fusarivoderasupekes.pdfIn PDF document text
    • http://sungder.com/upload/desemu.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16135c95241faa---81262567999.pdfIn PDF document text
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/gegefikipisoj.pdfIn PDF document text
    • http://poliinc.com/upload/files/zaxoragawovexebatebuwoba.pdfIn PDF document text
    • http://eia-edu.com/userfiles/file/24137702937.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_off0000b07a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c88c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC88C 15724 bytes
SHA-256: 07150341bcda52b1434996dedd554b19067bf90e266a977dea99012b024c4fc8
font_02_sfnt_off0000f0b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B9 10700 bytes
SHA-256: d6e59f235745039a6fee441b9ed1bd917530fae736ed5913f1e2700b781713f2