Malicious PDF — malware analysis report

Static analysis result for SHA-256 721550cf17fb4b98…

MALICIOUS

PDF

98.6 KB Created: 2021-06-28 13:57:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 9665e254411ba01a2ebe2f87d6ab7df0 SHA-1: 6c9449b43da2a0947f32508459cdf0c158067944 SHA-256: 721550cf17fb4b98ccff14124298ccb8e4f191cf2ea217e16ed2366fba3f94b1
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of multiple distinct hosts and a high number of links per host indicates a coordinated effort to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baca692166a---78460304305.pdf In PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/d0a7f7e51df820b275ee6510d447c430/mijudelatejozijivokiw.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc78964ce1b---xixaberavigagusifowo.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985360e3b89---dawimovitusafe.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/soxowi.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/321850b41fc2b0a8dd09f6e14570e100/88881493647.pdfIn PDF document text
    • http://sumterhigh89.com/clients/863574/File/28987381696.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/ee313ced2af1bf7daab49f6d25e879a6/viduf.pdfIn PDF document text
    • https://signika.pl/Upload/file/daladuvibapageren.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/zibiwi.pdfIn PDF document text
    • http://goodwynva.com/clients/d/de/de91e19d235d8a3764238851c6b73f99/File/fegotekeje.pdfIn PDF document text
    • http://greenbrier101.com/userimages/97887290720.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/1092666fd8ce88fe03cb6b7afcda854f/93532001053.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/6338432661.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/142271771ff9dc0fbeed26d26a207891/bapofiwetotovuzomug.pdfIn PDF document text
    • http://tafgambiatours.com/userfiles/file/subixom.pdfIn PDF document text
    • https://sieompaysdebray.fr/lesiom/txt/imgadmin/file/budozezizoji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=lithium+electrons+per+shellPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001033e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033E 10536 bytes
SHA-256: cd42663cacf0dd40e04dca363e6b872baf7bca944f9dcd1157ab288d8211653f
font_01_sfnt_off00011b07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B07 19932 bytes
SHA-256: 850c0a0ba2021eaa35c31df569c8d48cc7edbc2e55ef7f61297c8aa30e689fef
font_02_sfnt_off00014e3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off0001664c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1664C 16168 bytes
SHA-256: 1cfb00680a8a18ef5d5af493cc5b57cfe410abeba37087ee2ecd799c98b61e68