Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8db72cbcef81356…

MALICIOUS

PDF

70.3 KB Created: 2021-09-20 20:28:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5bd0f220781d0f8d46acaabca47a9c36 SHA-1: 7dfc1d403b425ad4093549fcc2b8d94d981b646c SHA-256: a8db72cbcef81356912baf28dc56ed2a7b5b30bda83e790da582ae54c9efee7f
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://vector-mebel.ru/uploads/files/roxosejapuronadux.pdf In PDF document text
    • http://yuhongzg.com/d/files/4067787449.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16140be68b1554---10410513097.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16147c8d82c4a1---kezetavajifuvojitisodod.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/f5182jolg91d1ss9clim1mk1d2/1663991020.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090416535033782.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136067c8d384---kuxitepivaw.pdfIn PDF document text
    • https://sanruouvang.net/images/uploaded/file/35505950556.pdfIn PDF document text
    • https://ksuskalology.com/images/file/12020560221.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/sebijalovadun.pdfIn PDF document text
    • http://soc-in.com/data/media/files/kasinen.pdfIn PDF document text
    • https://xn--23-6kci4asohe8k.xn--p1ai/userfiles/file/salazibudoruves.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16139d2b918bc8---fifodiremuvoviwafu.pdfIn PDF document text
    • https://feng-shuiworld.com/userfiles/file/piterotabukugojix.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/lodejof.pdfIn PDF document text
    • https://5703n1n6999-6a55.com/contents/files/99106852827.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/lavadipazejajunoxewexef.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/majitefudonidij.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161327e0e1f43a---91263544641.pdfIn PDF document text
    • http://clinicaveterinariaalbese.eu/userfiles/files/sekemopobotibofeva.pdfIn PDF document text
    • https://b7b.reviewz.eu/app/webroot/files/userfiles/files/35567004243.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161477bb574a96---digenez.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/72428440992.pdfIn PDF document text
    • https://digicpictures.com/downloads/1982540847.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=table+tennis+touch+mod+apkPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b1ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1CA 10972 bytes
SHA-256: 04e1abe8b8f3d2c3eb550dab3f4db24266e120ffc152c3ac8f2eff6d04f4401d
font_01_sfnt_off0000cadf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCADF 16628 bytes
SHA-256: d47e7754f843f3823957989994207036e8c544f5c29d3afc88ada2df4675818d
font_02_sfnt_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1