Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf891e2e0e13281a…

MALICIOUS

PDF

92.1 KB Created: 2021-07-30 01:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d1e60f7ef6c4464846e657e8aaec5fb0 SHA-1: f05610bbaf0459d5e778a959483065a9dc380fd2 SHA-256: cf891e2e0e13281a4c6949f5824e68294bfe2be5f983d37e19b3cca3ce07c89a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV both flagged this file as malicious, indicating a high likelihood of malicious intent. The primary function appears to be acting as a link farm, potentially for SEO manipulation or to distribute further malicious content.

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 http://photonart.nl/phpcmsys/file/paroxivabanezag.pdf
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a16d2425856---88896430092.pdf
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/s6n2jpnnqsglkot52u751i13qh/90950162212.pdf
    • http://briquettemachinery.com/d/files/29670859014.pdf
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210701_0205F57A5B279D0F.pdf
    • http://wych123.com/upload/files/65407916254.pdf
    • http://rococosofa.com/files/files/9968191572.pdf
    • http://barcelonasixtytwo.com/userfiles/file/58066886088.pdf
    • https://cavalier-hundezucht.ch/userfiles/file/kotera.pdf
    • http://cuspsurgeons.com/userfiles/file/78643733392.pdf
    • https://angkoronetour.com/userfiles/file/boximifus.pdf
    • http://colorfusion.us/admin/images/file/pukonaroval.pdf
    • http://getem.eu/files/file/64432761958.pdf
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bbb3bf52b---lareduvulomotekurefesala.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/7a0no5ssca7ec7tj4i8np1v66g/zukukinomo.pdf
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6db0156f2---21533364618.pdf
    • https://nikosdimos.gr/userfiles/file/fewon.pdf
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/cf5eeu0tc25i4reu9u4qeh53je/tikovaka.pdf
    • https://menu2uplus.com/images/file/radevipowodov.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/le28ruumgp67k7i6au4bffluo7/49887556199.pdf
    • http://mt-filtration.com/uploaded/file/39540355360bf291f94a02.pdf
    • http://jikaramen.com/uploads/files/62052387381.pdf
    • http://01host.ru/userfiles/files/90398692735.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=create+cursive+writing+practice+sheets+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010571.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10571 16792 bytes
font_01_sfnt_off00011d88.bin
83b59b07ab67eb7af79ee95a8b838393099a728a238127f3e80114ddf6996880
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D88 10876 bytes
font_02_sfnt_off000136b4.bin
44fb035777d0ecdb7c9134a44fafb1ac685350c8fd3db6a76fd45d3ea3bfe699
pdf-font-stream PDF embedded font (sfnt) at offset 0x136B4 16860 bytes