Malicious PDF — malware analysis report

Static analysis result for SHA-256 105540d7be5b8326…

MALICIOUS

PDF

77.5 KB Created: 2021-09-02 06:47:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: b7587d6ba295de85758f555933522fe9 SHA-1: 80416417a090b88d17a54af8d55c79f7337bde09 SHA-256: 105540d7be5b832622036f51ce80e74b25b41e59c315f4c54f10fa5dd290bc19
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. Numerous external URIs were extracted, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded URLs are consistent with a phishing attack, likely using a spearphishing attachment as the initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://crewmak.ru/uplcv?utm_term=clean+riddles+for+adults PDF link annotation
    • http://sns.hu/_user/file/95353800080.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b250ad7fd2b---66512477468.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aae01255997---17577092792.pdfIn PDF document text
    • http://aurora-c.jp/files/files/jazilipep.pdfIn PDF document text
    • http://klpa.net/userData/board/file/fewabut.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d1c31f74b---79720513694.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/45725033171.pdfIn PDF document text
    • https://bdprescription.com/ci/userfiles/files/lutoraguwiminadituruzudu.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/56627794538.pdfIn PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d24bd672b26---meluxazimajixobamunema.pdfIn PDF document text
    • http://minhquoc.vn/ckfinder/userfiles/files/mifonifeforitakime.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1606f50b8f12a9---26214690337.pdfIn PDF document text
    • http://marketypik.pl/zdjecia/fck/file/75125226298.pdfIn PDF document text
    • http://winkeleninzundert.nl/uploadimages/files/miturajetasex.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ad7271d96---3466209387.pdfIn PDF document text
    • http://ownlines.com/upfiles/file/70354444988.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/nakukoxosigivuseseba.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/b7e0794570d547575b6dbaddd3db0f0c/zedirisesebazegomefuwe.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/e92aa3112de9bd2282d40d495df8911c/32156308401.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/99kogt2o28lj6fsnb30nl4utt5/2552687153.pdfIn PDF document text
    • http://location-venise.com/italie_documents/files/selana.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d48a439c279---40561288114.pdfIn PDF document text
    • http://www.kymenhome-etsinta.net/tiedostot/files/seneju.pdfIn PDF document text
    • http://m3hotels.com/userfiles/file/80305528138.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b26fc2d602---70096502810.pdfIn PDF document text
    • http://remobudostol.pl/pliki/60527219761.pdfIn PDF document text
    • 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_off0000ccbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4D1 16948 bytes
SHA-256: 25a7d937fde3130ee42174226abdc172c6a33274984cf24d06e454dedaefb206
font_02_sfnt_off00011097.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11097 10476 bytes
SHA-256: 73f3c55675dea1d2fb1da282613d176f563fd8b2710c201eccaa4a02e87c1864