Malicious PDF — malware analysis report

Static analysis result for SHA-256 636c16afd6de0fab…

MALICIOUS

PDF

35.7 KB Created: 2020-06-11 22:40:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ce84afa622f3ec18671dfb10b5251ef5 SHA-1: e2e3cc38fc007bd311a89a3d06e7540827339364 SHA-256: 636c16afd6de0fabe3ad57740c2e03335e0db329726ac4f0de7d34b2e4201dad
96 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many of which point to other PDF files hosted on similar domains. The document body, though partially corrupted, contains references to 'Sylvac collectors guide' and the wkhtmltopdf tool, suggesting a lure to disguise the malicious intent. The ML classifier strongly flagged this PDF as malicious, indicating a high probability of it being used for phishing or distributing further malware. No scripts were extracted, but the extensive link farm is a strong indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://thesolarfarm.org/uploads/1/3/1/8/131871674/131871674.html#sylvac+collectors+guide
    • http://palmettocreditsolutions.com/uploads/1/3/1/3/131383342/jiveridutudumobeko.pdf
    • http://qnacleaning.com/uploads/1/3/0/8/130814208/migodalo_vudozudosizofa_gesaz_soxirevenifan.pdf
    • http://bronwynward.com/uploads/1/3/0/4/130476671/2487392.pdf
    • http://brookesaltus.com/uploads/1/3/0/4/130483862/tepoberivegij.pdf
    • http://simplenick.co.uk/uploads/1/3/0/7/130739210/ragexafevofe.pdf
    • http://victorydesignrestorationllc.com/uploads/1/3/1/8/131871517/d00547.pdf
    • http://autodiscover.objectsfound.com/uploads/1/3/0/9/130969498/gopazedot_nosedirixogu_nigegu.pdf
    • http://freemanforindiana.net/uploads/1/3/0/4/130476556/naxogojawex-riluxasu-murilajevuki-wenutewilo.pdf
    • http://inshopper.site/uploads/1/3/2/3/132302782/120905.pdf
    • http://dialtransportllc.com/uploads/1/3/0/2/130289453/376c90c9b3c049.pdf
    • http://blueraingutter.com/uploads/1/3/0/4/130488445/sotijor.pdf
    • http://teachingachildtoread.com/uploads/1/3/1/0/131070314/a6ec2a1bf76.pdf
    • http://cafe.clientdemo.co.nz/uploads/1/3/0/5/130539300/wagigojek_kavibuvepes.pdf
    • http://theperfectaccessory.org/uploads/1/3/0/6/130621772/kexaliruxowad.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://rajubap.files.wordpress.com/2020/06/37285701963.pdf
    • https://segurile782814837.files.wordpress.com/2020/06/16620520602.pdf
    • https://noginamopak.files.wordpress.com/2020/06/kelawod.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://scripts.sil.org/OFL

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005fc9.bin
390f90ab5a9ac595822ff636485638bb5f51af208d16d07db50afeb11a661f49
pdf-font-stream PDF embedded font (sfnt) at offset 0x5FC9 10560 bytes