Malicious PDF — malware analysis report

Static analysis result for SHA-256 99abd831f9809776…

MALICIOUS

PDF

87.8 KB Created: 2021-08-01 04:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 32cac638b1d79b724e0331e05ed86bed SHA-1: 4a4dcced4ecd31c3dba12545dc18a9cc545d79b8 SHA-256: 99abd831f9809776a39cf8f1e6af8edb424742626399e86b6b6125c2918dde51
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress upload directories, suggesting a phishing or spam campaign. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to redirect users to malicious sites or download further malware. No scripts were extracted, but the structure and URL patterns are indicative of a link farm used for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160adf7d540da8---90385974726.pdf
    • https://bosgo.mn/uploads/files/pelezufivipovafi.pdf
    • http://thanhtindesign.vn/uploads/image/files/11638622235.pdf
    • http://www.parkwaytransplant.com/media_upload/upload/files/36216955127.pdf
    • http://liavanhaeringen.nl/userfiles/files/9607942405.pdf
    • http://zuche0551.com/upload/file/gawizodimevedatixita.pdf
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160ad9a99524cf---50389683431.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0f9e1639e8---38521928653.pdf
    • http://peaktoppet.com/ck_imgs/files/69454717847.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075896933601---99897170922.pdf
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/iipddjp1mh8a7da42k2ud9mogs/81539167285.pdf
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/18ac73a599c3b72576241cdde6032286/vokuzamejadurotatoj.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae244fc4b5c---65896914513.pdf
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/34ff70d869d37256c23875bee350772d/14374392838.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/5edcb6f11a3952751d95ea3d3f4c2705/95127811124.pdf
    • http://angarakshaksecurity.com/userfiles/file/72980082172.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/5ed8f83a8cf03ff1ef65d2bbeeb9dfe4/42275686868.pdf
    • https://eltonltd.ru/sites/default/files/uploads/84908596194.pdf
    • https://zifu-tech.com/app/webroot/userfiles/files/giwizedoxogivabi.pdf
    • http://eksan-ltd.com/userfiles/file/11356884792.pdf
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/3a8abc48e7a6444f0032efa83ebed035/nidibitomuxumafenurezoves.pdf
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a638d55eab0---kijejotavefivo.pdf
    • http://kmkonsult.cz/userfiles/file/vifalasunugo.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/6e4gp6csv9kg6s2ks11dc3cun0/sotuzikexaseza.pdf
    • http://adveotec.com/img/file/jusoper.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=hospital+discharge+letter+example
    • 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_off0000f2dd.bin
f3ec4b963d0f32a780e5392a3c8e290b9e4b92e508ec09dc42ef77f8c7e0bd35
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DD 17324 bytes
font_01_sfnt_off000120b2.bin
c0da7866f6e5815c51df91d0ec6952a48036aee7008a52e1428178114e1e69d3
pdf-font-stream PDF embedded font (sfnt) at offset 0x120B2 10952 bytes
font_02_sfnt_off000139e4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x139E4 16792 bytes