Malicious PDF — malware analysis report

Static analysis result for SHA-256 13d953ba37b8fa23…

MALICIOUS

PDF

87.3 KB Created: 2021-07-19 16:17:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 48a4ea6d08e007b52a07735105ecce19 SHA-1: a0ced971b71770330448c25230fd8eb1c3c9774d SHA-256: 13d953ba37b8fa23a46d6b4dc00318086d1dd63f668d53293516db318ab6b481
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, flagging it as a phishing trojan. It contains a link farm with numerous URLs pointing to compromised CMS uploads, suggesting an attempt to lure users to malicious content. The document body is unreadable, but the heuristics indicate a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c809867c2---xinumexelatulovaseson.pdf In PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160edd1758dad1---15531002777.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160894e9c8cb53---68020806311.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/nusobe.pdfIn PDF document text
    • http://djarkitek.com/temp/vinney/HTML/userfiles/file/vetop.pdfIn PDF document text
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/jokororup.pdfIn PDF document text
    • https://highrise.pl/file/funati.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/78832820628.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b70072eb64b---54851270668.pdfIn PDF document text
    • http://www.huntsvillepr.com/files/files/bosiw.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/fudewuvasebegiv.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160decb805a3af---tarozedudedaba.pdfIn PDF document text
    • http://rchs1964.com/clients/5/58/580abc73d3aac4ea3a2bdd7c75327783/File/23694491965.pdfIn PDF document text
    • http://punaide.com/userfiles/files/90007485317.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/40750214498.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/isa4l76bqd3ohivth25dkrcjj5/bojubezife.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c9b9415ea---lubidinatu.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/508edcd9799bd49530413f325069768d/koduvotosad.pdfIn PDF document text
    • https://alperbehang.nl/userfiles/file/lidewedomopazolami.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097faff25ec6---18802619033.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/c5f5fa13e9b762fcd1ca74465c77e8f9/31877069109.pdfIn PDF document text
    • https://advertisementnepal.com/ckfinder/userfiles/files/82629341532.pdfIn PDF document text
    • https://waroproject.com/file/finadenuwetajuwikazusipow.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/52389088512.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/beedc67c8e9ba71a77f4b91a5bfff8ca/2770734677.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=blackpink+before+and+after+plastic+surgeryPDF 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_off0000ed22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED22 11292 bytes
SHA-256: 7f51bd6a4d1f60daae1174811a7b791b8e12aa6ce656ca8b754659fd8c5828b5
font_01_sfnt_off0001076e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1076E 17688 bytes
SHA-256: 0190e2e16d0438bd73d718227be35e5075b4a3ef9b44d8bb254a89f5b5fefc92
font_02_sfnt_off000135be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1