Malicious PDF — malware analysis report

Static analysis result for SHA-256 64b88bb1135a36b7…

MALICIOUS

PDF

102.8 KB Created: 2021-07-04 01:25:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: efb049cbfd195cd67b1e4970da3b6d84 SHA-1: a5e372cd95331724bbf08acf2e7e97121b889078 SHA-256: 64b88bb1135a36b79eee90ed6494c32fecb2a9612edc7ebd7af607edbbf040fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm directing users to multiple external URLs, with several hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic findings and numerous URLs point to a malicious link farm designed to lure victims.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://straub-online.ch/userfiles/files/67879593334.pdf
    • https://penzionradvanice.cz/res/file/51681688573.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba99a3d615---murulugefufogukur.pdf
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/bdb88a1c7e2613e5501dda64c7236041/53357005252.pdf
    • http://kjphotocon.org/data/userfiles/files/87644659342.pdf
    • http://bluecars.pl/userfiles/file/92980876001.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/qaf4ljd3qh9a4b08q0d8u5nv2f/32313045605.pdf
    • http://proxima-design.cz/files/file/sawaxiletomipiletikopug.pdf
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/khuqriknv8cp8e2jme7k9pa44j/19339756786.pdf
    • http://asea-admin.com/_userfiles/file/20210630073002.pdf
    • http://gumberryoleschool.com/clients/33891/File/58145451480.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/bspohghvt55hi4nkk55k6rvnl2/bojabujuwipubelarafupejan.pdf
    • http://sam-global.ch/files/file/tobaretogizixu.pdf
    • http://romanakladatelstvi.cz/userfiles/file/pepifeninonetexo.pdf
    • http://abpaluso.com/upload/file/17077905780.pdf
    • https://alianzatours.com/imagenes/file/mutugot.pdf
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/4b87ce50aae0faaf8686667c62d9de78/33400585164.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160beed5a06b27---suzoxodanimexulidunemeg.pdf
    • https://batikatravels.com/userfiles/file/lumomuxikanofesinujedot.pdf
    • http://chonburi33.com/userfiles/file/wogudujorilojunovazunanix.pdf
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd083ed548---guvulotefubigomini.pdf
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29a7dbf6b0---9441393372.pdf
    • https://evergreencans.com/userfiles/file/53196176323.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=receptive+language+goals+speech+therapy
    • 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_off00012d2a.bin
17863dfbe4d0989b12632f9cb0def81dfff4ee56431eb89ed98aae1f26dcd4d0
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D2A 18340 bytes
font_01_sfnt_off00015c2d.bin
e6b80598a63b5894d8f5b185de1bba724cb5007b657a1d43f5acba37752fd8e3
pdf-font-stream PDF embedded font (sfnt) at offset 0x15C2D 10976 bytes
font_02_sfnt_off000175af.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x175AF 16792 bytes