Malicious PDF — malware analysis report

Static analysis result for SHA-256 43581320b0d6a734…

MALICIOUS

PDF

97.3 KB Created: 2021-09-06 16:52:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 88a76fd09c556f94dafb5a36b9397f42 SHA-1: 598e5e99ae09f110a84bf871a554a0baf7e707f8 SHA-256: 43581320b0d6a73429acbea7e9a84782d0efe43927ac23ec99a2446d6fa61196
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are hosted on disposable domains, suggesting a link farm designed to distribute malicious content or phish users. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate effort to obscure the final destination and leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://nepaltrekkinginhimalaya.com/assets/userfiles/files/33097064229.pdf In PDF document text
    • https://an-professional.ru/img/files/file/82510468059.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/82c46c9dfe23e16e1ece75d2de31a74c/30445232012.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/panoregegarovukinazix.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606eee10c1110---48380247090.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41041c48db---refenegukaxik.pdfIn PDF document text
    • http://perfekttorun.pl/pliki/20780918171.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/p1fdig58a9h1ckf507um3p60eg/valavaxanelunilo.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609d32e9d50e7---kobupeg.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16129d44cbe0ce---19727106784.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3f989e25a---33314704489.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd9b6e41924---buvuvumuzinubakenamine.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/4a395493205887ef43b1db38927567a2/witat.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/jaluwobinili.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/44656092040.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210904120036.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/cqn1ceqrbi7r394iro08pggl22/jufimaxu.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/23anbdmm4r5u8kv2o5f608hs03/91096638297.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/vamuvilizijirejido.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/febawojajexetet.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/hh3h8ngv3833e07mncu7qjqu41/77180791234.pdfIn PDF document text
    • http://townsendrogersfamilyreunion.com/clients/9/91/912616e09393d205379ff76530a10a1f/File/66857391794.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/vufarakurisi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=tumor+lysis+syndrome+%E0%B8%84%E0%B8%B7%E0%B8%AD+pdfPDF 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_off00011547.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11547 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012d59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D59 18340 bytes
SHA-256: 3233df6069a0e9d69f21742cae79600f145683faac130a6691bc7d2539678cad
font_02_sfnt_off00015d5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D5C 10576 bytes
SHA-256: 23eb4fb0674d44a4c29e78f44700603a4ca776a687600236277e4993132c7959

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