Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c76be624fe12085…

MALICIOUS

PDF

82.4 KB Created: 2021-09-13 13:53:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: edfa897b1c82e823faed092e882d6241 SHA-1: 8ca9c71b77cafd34e0e60d2b35e3164dee9c6e2a SHA-256: 4c76be624fe1208571d8efa0877fe17dfb1067be903ddc4afa0c6349d1323645
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external URLs, some hosted on potentially compromised or disposable domains. The presence of numerous links on disposable hosting and the use of UTM parameters suggest an attempt to obscure the true destination and potentially engage in SEO-based phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://pietroquatriniarchitetto.eu/userfiles/files/61209299090.pdf In PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5158147e7---xosojuposu.pdfIn PDF document text
    • https://edgecs.com/documents/75345221408.pdfIn PDF document text
    • http://acelybio.com/upload/files/49574214988.pdfIn PDF document text
    • https://tourgardan.com/basefile/tourgardancom/files/33293173024.pdfIn PDF document text
    • http://zssadkowice.pl/pliki/54121820260.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/65396500678.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/dexisizigi.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/5772338676.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/76003beb0779970bdd5be67a86e284fb/mugadi.pdfIn PDF document text
    • http://saigonradio.com/userfiles/file/21846951136.pdfIn PDF document text
    • https://maviet.vn/upload/files/ziviru.pdfIn PDF document text
    • https://srilangkapools.com/contents/files/xebuwonul.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/luramutipinowepub.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/motosumonuti.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612feef6382f5---16779826179.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/vugaxoluzizut.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/30006992381.pdfIn PDF document text
    • https://equalland.com/uploads/File/78077452531.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb5f021858---60804955105.pdfIn PDF document text
    • http://chinhlytailieuluutru.com/media/ftp/file/bemevinebusorazege.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/mumiloso.pdfIn PDF document text
    • https://kit-veron.my/ckfinder/userfiles/files/79796519274.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=group+call+botimPDF 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_off0000de70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE70 10412 bytes
SHA-256: cf9ee36b539e914a3896522ec4d164853c46ce9de91467f2cf02613597c271ea
font_01_sfnt_off0000f5ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CA 17932 bytes
SHA-256: f2a7bdbbd73eb12ec9321883d15cc5753b1ad9808585906e345e77500fa2c849
font_02_sfnt_off00012438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12438 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1