Malicious PDF — malware analysis report

Static analysis result for SHA-256 7355fd4151ed0411…

MALICIOUS

PDF

85.6 KB Created: 2021-09-10 22:10:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2fbdde2738d28d482b62d48462a9e11c SHA-1: 160fe45f10c08200a76d4c8eb66ef1b8d4352e95 SHA-256: 7355fd4151ed0411a628b7fcb17cac418b59b5d5189104fdfc5eb5598f7e584e
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 ML classifier and ClamAV, with heuristics indicating it functions as a link farm. Several extracted URLs point to compromised CMS upload directories, suggesting an attempt to host malicious content or redirect users to phishing sites. The document body is unreadable, but the presence of numerous external links and the 'link farm' heuristic strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://stl-log.com/htdocs/cljr/data/files/39934580672.pdf In PDF document text
    • http://85560891.com/upfolder/e/files/20210910150118.pdfIn PDF document text
    • https://franciscovalles.comtraining.cl/userfiles/files/kokagisuxapegokuru.pdfIn PDF document text
    • http://baove24h.info/upload/files/20081825979.pdfIn PDF document text
    • https://keluargamimpi2.com/contents/files/52308235165.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/ferazurufetimijugokufu.pdfIn PDF document text
    • http://materialdeestudo.top/userfiles/files/jagegikoliw.pdfIn PDF document text
    • http://ukrkarta.ua/fckeditor/userfiles/file/74839554405.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328fca8de08---73238799193.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/62666337683.pdfIn PDF document text
    • https://bibliotheque-des-arts.ch/ckfinder/userfiles/files/zekikivemutatifow.pdfIn PDF document text
    • http://tce.vn/imagesflashupload/file/gajusopolife.pdfIn PDF document text
    • https://tumujerrusa.com/userfiles/3284281006.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161313905a671a---gugewijewit.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133342c07b40---461132638.pdfIn PDF document text
    • http://rulife.ru/ckfinder/userfiles/files/24868842354.pdfIn PDF document text
    • https://s-oil.hoakhanh.vn/uploads/image/files/votawujuwaremumibajidotu.pdfIn PDF document text
    • http://africanhairbraidingsalon.com/userfiles/file/77752181944.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/37835135211.pdfIn PDF document text
    • http://vetcasatenovo.it/userfiles/files/woxajetulejoxafi.pdfIn PDF document text
    • https://anandamsanyal.com/userfiles/file/28885668766.pdfIn PDF document text
    • http://papaicountrylodge-longstay.com/user_img/files/wexuretudimijelakod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=the+walking+death+onlinePDF 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_off0000e978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE978 18432 bytes
SHA-256: 0e03573fa640029257d322f1769e9330dbb3568fc9f96baa50d207300bc60e1f
font_01_sfnt_off00011945.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11945 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001315c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1315C 10400 bytes
SHA-256: 768b5e0f9807b0677cf6401e08d52348c14c8bc27139988bc4fc10021b290812