Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ff87f529ee194f2…

MALICIOUS

PDF

103.2 KB Created: 2021-07-04 18:51:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4b52bbf3c0168a79216b0fffb7f9e56e SHA-1: 921cf1293eb58dc31b06d1f7c416420358868c4c SHA-256: 4ff87f529ee194f28fdaf04a196b489851474bc454efbc32ea5e595dfa0ad3bb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to numerous compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple links on disposable hosting and compromised CMS uploads further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

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://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160acd6e13c85d---wagexekodasigelukefo.pdf
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/qgtou758q785887e19k9htiq32/riledet.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160908b7e8e587---60702682620.pdf
    • http://akinmedical.com/uploads/file/rikasupowum.pdf
    • https://jahanchart.ir/data/files/file/14768186404.pdf
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/968bfcc1b288d05bd12a2cc06152eb41/41969275221.pdf
    • https://shibbirs.com/media/files/54604767631.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16071786375085---14570689394.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16090220f36bef---276086292.pdf
    • https://altaspin.com/calisma2/files/uploads/61013441950.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160884be6aef93---kofoluze.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609623151af10---suzenimibo.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/f0495ba7bf7a23b9c89a1c5d5a9e7aed/27108973159.pdf
    • https://celebicatering.com/upload/ckfinder/files/depimowebisapa.pdf
    • https://tempegaring.com/contents//files/busuwifemepizizuteg.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/cjo8skenad1k69vuplsg00u6go/33644998067.pdf
    • http://mtcclassof81.com/clients/0/0a/0a45bd3013a8cc77df817aa526a911b1/File/61357144186.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/abe8lkea6cnttorbmg1k33mboe/29956254716.pdf
    • http://skybuildinfraprojects.com/uploads/kuzutiginakumiledudis.pdf
    • http://funperm.ru/content/file/dekazafode.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1609a056f6166e---9232496324.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768a2c05841---3427459880.pdf
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/d0c6376bc9dc20ce817212317465fbd3/ropadijuporumiked.pdf
    • https://universal4shipping.net/userfiles/file/kutobe.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=person+in+philosophy
    • 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_off000130f6.bin
6bad3163fba2d283816933117161f06b188b452fd41738414878c240d60bcc91
pdf-font-stream PDF embedded font (sfnt) at offset 0x130F6 18480 bytes
font_01_sfnt_off000160bd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x160BD 16792 bytes
font_02_sfnt_off000178d4.bin
5f3183f748af722ef9caf607b32e42e4156b2eea4daa1ec97d8e85458c8e185f
pdf-font-stream PDF embedded font (sfnt) at offset 0x178D4 10204 bytes