Malicious PDF — malware analysis report

Static analysis result for SHA-256 8dd0136f7d2b7dd1…

MALICIOUS

PDF

81.8 KB Created: 2021-09-06 04:17:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c5baf78c834f8193521d9e01c0878b15 SHA-1: 2be9eeac91a98ea1465154c8b06f143b2906abba SHA-256: 8dd0136f7d2b7dd178466895e1991ffd984f84ee57b05798b29584efac89862c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to potentially compromised websites or disposable hosting, suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF structure itself are indicative of an attempt to redirect users to malicious content, possibly for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://tjsijiqing.com/ckfinder/userfiles/files/2021/0823/015c6cb71dd90b633a611882b5e56e6d.pdf
    • https://stillwaiting.org/userfiles/file/43298937656.pdf
    • http://cn-junsheng.com/upload/file///202175114624298.pdf
    • https://www.hkha.com.hk/ckfinder/userfiles/files/68867515173.pdf
    • https://almoheetmanpower.com/public_html/userfiles/file/50847692982.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160ddfed779fa6---tanekirav.pdf
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/731q9872p3dd8bojao0ek3urb4/66449925753.pdf
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/71e22475c7fc8fed91f0e521ac537f0d/dafodamufunid.pdf
    • https://fiberglasssupplydepot.com/userfiles/files/rusumisixise.pdf
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160737e2ff09b3---33798323651.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b90727c11c6---zapigalusodiraloxato.pdf
    • https://spiuruguay.com/ckfinder/userfiles/files/danipidubifogafuzam.pdf
    • http://agriturismocorteerbatici.it/userfiles/files/16405648170.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/5372c67aeb3b5cb8b05ac08357cdc7e0/47801598317.pdf
    • http://ff-engineering.com/userfiles/files/vabovizu.pdf
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/sasinidozalomadaw.pdf
    • https://magiccat.pro/ckfinder/userfiles/files/57111801281.pdf
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d047d6ae5---69274026274.pdf
    • https://msvadba.ru/files/file/dewel.pdf
    • https://angkortaxiservice.com/userfiles/file/nijewitutufubipij.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/7d7d9789b978e78952b073ccbd1e6df6/bunowemur.pdf
    • http://yomamasushitogo.com/uploads/files/mukujinasiz.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/5hmrhpuoojji5d39qfk8799o67/22104369446.pdf
    • https://greffedecheveux.center/upload/ckfinder/files/fevabadamaxeboteg.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=potentiometer+working+principle+pdf
    • 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_off0000d834.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD834 16792 bytes
font_01_sfnt_off0000f046.bin
8f0e04fdba86da5802915fe86434a6e0a81e662d0c5ed63ce4381001540faa39
pdf-font-stream PDF embedded font (sfnt) at offset 0xF046 18636 bytes
font_02_sfnt_off000120c1.bin
7a651079d3979431681cc04bb0c85fef96b9148d82bb1a2449497119f9e5dbdf
pdf-font-stream PDF embedded font (sfnt) at offset 0x120C1 10812 bytes