Malicious PDF — malware analysis report

Static analysis result for SHA-256 087ba8a121bb4558…

MALICIOUS

PDF

77.3 KB Created: 2021-09-15 15:58:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 65a3e36d2799d6f09977207e8bdd7651 SHA-1: a86ddc6dcaa8e68e4815551a40b338ba985ee503 SHA-256: 087ba8a121bb455852a3a4e8e800261be665db550c2fd501a19941d91b749a49
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.012 Process Injection T1204.002 Malicious File

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://writtenmail.com/upload_images/file/pavijadesomakogijuxuvase.pdf
    • https://noriupapildu.lt/ckfinder/userfiles/files/texanabozopemokumelim.pdf
    • https://www.passion-rnd.com/upfile/files/2021/09/13/pefolovupadi.pdf
    • http://daindnc.com/fckeditor/userfiles/file/sifozurasomujurifapejisib.pdf
    • http://seychelles-resort.com/images/blog/file/14482280895.pdf
    • https://anna-bel.com/app/webroot/files/userfiles/files/tilox.pdf
    • https://fong-cai.com/upload/files/garanujurubavokejifesifu.pdf
    • http://aburobocon2019.mnb.mn/uploads/files/15036043595.pdf
    • http://yibetter.com/data/files/33772352067.pdf
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/mkscmg0o8k95dh8a2kn8h0h0hn/zevisozodusevoti.pdf
    • https://fratellifurloni.it/file/julazukol.pdf
    • https://bank-kredit.at/ckfinder/userfiles/files/9186427676.pdf
    • http://ytbozhuo.com/upload/file/151413306793.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/u36nflm421m0srt6t5fk6lk0ff/kulurajeposebutovusomore.pdf
    • https://contemporaryteas.in/admin/uploads/file/38897020184.pdf
    • http://ltpbetel.ro/userfiles/file/niriwonajepitim.pdf
    • http://espressobuilders.com/app/webroot/files/userfiles/files/65848541407.pdf
    • http://geriatriccarenewjersey.com/userfiles/files/92865072873.pdf
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/s6jksr3hlphd3sb2l25ehldvl3/70035129600.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140e8424afa8---17749661143.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16136e1b313499---97822447929.pdf
    • http://hyswimpool.com/userfiles/vufigexodetenotidixe.pdf
    • https://solener.info/ckfinder/userfiles/files/26476481075.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=best+language+app+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca5b.bin
ca46526aa84ca0ba8c597bc8da5979ef2628de50fd17e40f49d5b3400e819b1e
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5B 17088 bytes
font_01_sfnt_off0000f6b9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B9 16792 bytes
font_02_sfnt_off00010ed0.bin
bca5abdc790b11c2fbef245f5993c20dec724bc88dc21c855bd38a9d31eae42d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED0 10720 bytes