Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c13c3d620a3d00…

MALICIOUS

PDF

87.7 KB Created: 2021-07-23 21:13:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 96a9eacc743962d3ddd3a1d5564686f9 SHA-1: f7a288d4585f48db2d8162bbde99852c74aa52f9 SHA-256: 27c13c3d620a3d00ea006a6a957be67d56accd0fa0c682ea7c28d4ea224700fb
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised CMS upload directories, suggesting an attempt to host or distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The presence of multiple compromised host links and a link farm structure points towards a tactic to obscure the ultimate destination or to leverage SEO poisoning for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5e14b6b72---jijizuvavofo.pdf
    • http://danguykhoidoanhnghiephp.vn/Upload/files/fativefurojelakinizan.pdf
    • http://eventechsite.com/files/files/98936475718.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/9914e4b25e28eccc9ddc512c1db38cdc/83034452985.pdf
    • http://komputerzagrosze.pl/userfiles/file/mifesivowejaxereboxekos.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093cdc7b71a2---fadujumewo.pdf
    • https://detmers-kontejner.hr/files/85415200560.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/90c9b6bc58a78efff68cd422354536cd/jiguwexekivalepavimiw.pdf
    • https://sankaibearing.com/userfiles/files/finevifevog.pdf
    • http://dansecyr.ca/pdf/file/dobijaxes.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/fd086a8a2a89d3410c45c9f98d42d428/14755059280.pdf
    • http://rszm88.com/upfolder/e/files/20210531150512.pdf
    • http://rghsalumni.com/clients/82979/File/5307671496.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed2dcd7bd7---sireliwo.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd99d7d658---34418675092.pdf
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/poxobobimoxowasuxefepajut.pdf
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab8237579a---50227755029.pdf
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/47862365936.pdf
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b40152f088c---2457780723.pdf
    • http://anjilh.com/uploadfile/file///2021050112010678.pdf
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/1amt58qcgtac8vg0q6jh5roup6/15115117178.pdf
    • https://mimpishio2bet.com/contents//files/gafapumukidirimazi.pdf
    • http://smit-electronic.hr/upload/datoteke/42046477338.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=what%27s+vegetarian+at+panda+express
    • 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_off0000f35d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF35D 16792 bytes
font_01_sfnt_off00010b74.bin
c04ca798a9e9ad496652e482a621f05a80f09657b8b063ab7731dd3e19a6e95d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B74 10700 bytes
font_02_sfnt_off000123d2.bin
b6cadbb6b4b2349fc8a040f2a805a210fa5a6cd7bb404a44a2a351fdf98f35f1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123D2 17296 bytes