Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bbb172cfe187696…

MALICIOUS

PDF

70.4 KB Created: 2021-09-17 20:17:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d53440f7ff5b16207ea87e5517a46ecc SHA-1: a49da8e6e86c4f46003c11d92183ac747493eebf SHA-256: 5bbb172cfe187696d9a5e2332f8428bf52157ed1d9d10a717def814f4fff32b5
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, detecting it as a phishing trojan. Numerous embedded URLs point to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates this pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://nomylo.ru/uplcv?utm_term=full+scientific+calculator+pro+apk PDF link annotation
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/54150822933.pdfIn PDF document text
    • http://dobermanncz.eu/files/97972793000.pdfIn PDF document text
    • https://ikincielinmak.com/upload/ckfinder/files/42547392058.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613cffa8cde39---19727241558.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/xoxumulibumikukevoluj.pdfIn PDF document text
    • https://lrdreamteam.com/files/files/file/InfoProduct/file/61326280781.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/fodukiduwodesolovux.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-7/20210907230459794464.pdfIn PDF document text
    • https://heureka-cz.eu/files/sememe.pdfIn PDF document text
    • https://keluargamimpi.com/contents/files/93527769165.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/jixawavoje.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/75206217994.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa6684ef33---nujowijolomigoxata.pdfIn PDF document text
    • http://juentai.com/userfiles/files/guxixugulumedewidanoga.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/77061014292.pdfIn PDF document text
    • http://njxinbell.com/upload/files/nazuxigen.pdfIn PDF document text
    • http://talani.nl/userfiles/image/file/89465597982.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/doxete.pdfIn PDF document text
    • http://stillincontact.com/images/mails/file/gexunijirozisatemetuwuke.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7d8be39cb---81895582467.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/47224980844.pdfIn PDF document text
    • http://thepokewave.com/uploads/files/pajulamivaxidolixamamu.pdfIn PDF document text
    • http://norilsk.torbay.ru/images/uploads/file/gasedikibuvi.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/begifizabato.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/sozigezexinirokigutatug.pdfIn PDF document text
    • 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_off0000b614.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB614 10640 bytes
SHA-256: 5757f52477c85b5279fe909c03f81ee0a9b361e6bcb355a611adafd2d4732ea0
font_01_sfnt_off0000ce8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE8F 14876 bytes
SHA-256: a94081c6741f25cefae41a9cd0b64cf7269c2f0f45137db533fa9733f2afe4a6
font_02_sfnt_off0000f3e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1