Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f81bd7fc01796a1…

MALICIOUS

PDF

86.7 KB Created: 2021-09-11 13:23:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ac9a1bd06d8ccf50f3d9d26d9eff1f65 SHA-1: 1a3b65b367b42f663038bdd1e3d23a6203b6440e SHA-256: 6f81bd7fc01796a155d2e78aab86efd6cb947d2cc7299a34824f3dd3921d271d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The sample is a PDF file detected by ClamAV as Pdf.Phishing.Trojan-d2568dad23a94d95. It contains embedded JavaScript and multiple external URIs, some of which point to compromised CMS upload storage. The ML classifier also flagged this PDF with high confidence. The embedded JavaScript likely attempts to download and execute a second-stage payload from one of the linked URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9875

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/ed2d4120364faac34f7b4b435b25b59d/vawesemoze.pdf
    • https://memorybg.net/app/templates/js/ckfinder/userfiles/files/93137339524.pdf
    • https://pcparts.fr/ckfinder/userfiles/files/jivekudazigoviv.pdf
    • http://simsoncantho.com/userfiles/file/1341313254.pdf
    • http://eyupsifalibitkiler.com/resimler/files/9735767843.pdf
    • http://aurastaffing.es/upload/file/dosunofobaj.pdf
    • https://tfsroanoke.com/home/tfs/public_html/new/ckfinder/userfiles/files/bipipi.pdf
    • https://elger.cz/fckphotos/file/niveruxubinatuxusobo.pdf
    • http://glassick.com/userfiles/file/67637848155.pdf
    • http://www.sm.ac.th/ckfinder/userfiles/files/dugufelunedagi.pdf
    • http://jyjjapan.jp/files/ckeditor/files/belogatina.pdf
    • http://jlicentral.com/images/authors/file/5672395964.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613413b1c80fa---52764361281.pdf
    • http://xn--80aejmo0alc.xn--p1ai/ckfinder/userfiles/files/95542981677.pdf
    • https://nibrasimansch.com/userfiles/files/92116086378.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/ef74523d909cc4ed0df1de1fb168cdb6/zowatixikudepimogawibi.pdf
    • http://animationcoach.com/userfiles/file/82752776779.pdf
    • http://flapboxes.com/userfiles/files/kipive.pdf
    • http://parzenica-bialka.pl/userfiles/files/sewebojetiwigonaluxovele.pdf
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/waduvatasuden.pdf
    • http://eco-building.cz/UserFiles/File/jumogefiberi.pdf
    • http://sungwoo-n.com/userfiles/file/gedage.pdf
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/76777200060.pdf
    • http://plymouth-logs.co.uk/ckfinder/userfiles/files/67578209748.pdf
    • https://aradovan.com/userfiles/file/zosaronulofijozo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=percy+jackson+and+the+olympians+the+last+olympian+pdf
    • 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_off0000ed1c.bin
5f831939e647891af8702cb55a0b966d8943a1faa992be14183792774c3fbc73
pdf-font-stream PDF embedded font (sfnt) at offset 0xED1C 17608 bytes
font_01_sfnt_off00011acb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ACB 16792 bytes
font_02_sfnt_off000132e2.bin
f4bef74fc78d2ce9dd7070425b3f4cfabfbd183d4b184b040143906bd4554b80
pdf-font-stream PDF embedded font (sfnt) at offset 0x132E2 11220 bytes